Why is mp4 video not showing in chromium?

Question

Google Chrome

I add two mp4 videos to the page through the html5 tag. One works, and the second only sound.
Here is what "exiftool" outputs about a video that works:

ExifTool Version Number         : 10.60
File Name                       : 30210028_241808509697113_8583185536225640448_n.mp4
Directory                       : .
File Size                       : 3.5 MB
File Modification Date/Time     : 2018:04:11 14:53:20+03:00
File Access Date/Time           : 2018:04:19 11:35:17+03:00
File Inode Change Date/Time     : 2018:04:11 14:53:20+03:00
File Permissions                : rw-rw-r--
File Type                       : MP4
File Type Extension             : mp4
MIME Type                       : video/mp4
Major Brand                     : MP4  Base Media v1 [IS0 14496-12:2003]
Minor Version                   : 0.2.0
Compatible Brands               : isom, iso2, avc1, mp41
Movie Header Version            : 0
Create Date                     : 0000:00:00 00:00:00
Modify Date                     : 0000:00:00 00:00:00
Time Scale                      : 1000
Duration                        : 0:00:35
Preferred Rate                  : 1
Preferred Volume                : 100.00%
Preview Time                    : 0 s
Preview Duration                : 0 s
Poster Time                     : 0 s
Selection Time                  : 0 s
Selection Duration              : 0 s
Current Time                    : 0 s
Next Track ID                   : 3
Track Header Version            : 0
Track Create Date               : 0000:00:00 00:00:00
Track Modify Date               : 0000:00:00 00:00:00
Track ID                        : 1
Track Duration                  : 0:00:35
Track Layer                     : 0
Track Volume                    : 0.00%
Image Width                     : 640
Image Height                    : 640
Graphics Mode                   : srcCopy
Op Color                        : 0 0 0
Compressor ID                   : avc1
Source Image Width              : 640
Source Image Height             : 640
X Resolution                    : 72
Y Resolution                    : 72
Bit Depth                       : 24
Video Frame Rate                : 30
Matrix Structure                : 1 0 0 0 1 0 0 0 1
Media Header Version            : 0
Media Create Date               : 0000:00:00 00:00:00
Media Modify Date               : 0000:00:00 00:00:00
Media Time Scale                : 44100
Media Duration                  : 0:00:35
Media Language Code             : und
Handler Description             : SoundHandler
Balance                         : 0
Audio Format                    : mp4a
Audio Channels                  : 2
Audio Bits Per Sample           : 16
Audio Sample Rate               : 44100
Handler Type                    : Metadata
Handler Vendor ID               : Apple
Encoder                         : Lavf56.40.101
Movie Data Size                 : 3672686
Movie Data Offset               : 39671
Avg Bitrate                     : 828 kbps
Image Size                      : 640x640
Megapixels                      : 0.410
Rotation                        : 0

Here's the video that doesn't work:

ExifTool Version Number         : 10.60
File Name                       : htKQ9cJfMPLCdC-2NvkuXgrD5OoKd2P9.mp4
Directory                       : .
File Size                       : 39 MB
File Modification Date/Time     : 2018:04:19 10:30:16+03:00
File Access Date/Time           : 2018:04:19 10:31:11+03:00
File Inode Change Date/Time     : 2018:04:19 10:30:16+03:00
File Permissions                : rw-rw-r--
File Type                       : MP4
File Type Extension             : mp4
MIME Type                       : video/mp4
Major Brand                     : MP4  Base Media v1 [IS0 14496-12:2003]
Minor Version                   : 0.2.0
Compatible Brands               : isom, iso2, mp41
Movie Data Size                 : 40270259
Movie Data Offset               : 44
Movie Header Version            : 0
Create Date                     : 2018:02:13 14:43:38
Modify Date                     : 2018:02:13 14:43:38
Time Scale                      : 1000
Duration                        : 0:13:48
Preferred Rate                  : 1
Preferred Volume                : 100.00%
Preview Time                    : 0 s
Preview Duration                : 0 s
Poster Time                     : 0 s
Selection Time                  : 0 s
Selection Duration              : 0 s
Current Time                    : 0 s
Next Track ID                   : 3
Track Header Version            : 0
Track Create Date               : 2018:02:13 14:43:38
Track Modify Date               : 2018:02:13 14:43:38
Track ID                        : 1
Track Duration                  : 0:13:48
Track Layer                     : 0
Track Volume                    : 0.00%
Image Width                     : 640
Image Height                    : 368
Graphics Mode                   : srcCopy
Op Color                        : 0 0 0
Compressor ID                   : mp4v
Source Image Width              : 640
Source Image Height             : 368
X Resolution                    : 72
Y Resolution                    : 72
Bit Depth                       : 24
Video Frame Rate                : 29.97
Matrix Structure                : 1 0 0 0 1 0 0 0 1
Media Header Version            : 0
Media Create Date               : 2018:02:13 14:43:38
Media Modify Date               : 2018:02:13 14:43:38
Media Time Scale                : 44100
Media Duration                  : 0:13:48
Media Language Code             : und
Handler Description             : SoundHandler
Balance                         : 0
Audio Format                    : mp4a
Audio Channels                  : 2
Audio Bits Per Sample           : 16
Audio Sample Rate               : 44100
Handler Type                    : Metadata
Handler Vendor ID               : Apple
Encoder                         : Lavf54.63.104
Avg Bitrate                     : 389 kbps
Image Size                      : 640x368
Megapixels                      : 0.236
Rotation                        : 0

Why is this and how to fix it, please tell me.