Why does the video take so long to render?

Question

Video processing

A 20-minute video from GoPro (4k, bitrate) has been rendered for 2 hours and shows another 8, almost no changes have been made, added subtitles, superimposed pictures in some places, played around with the sound - that's it.

My laptop is MSI gf75 thin 9sc
i-7 9750h
gtx 1650
16 gb 2666
Before that, everything was fine, such a video would have been rendered in a maximum of an hour and a half earlier.
I didn’t change any settings, I cleared the cache for a long time, maybe a month ago, it’s rendered on ssd, I even restarted and set the bitrate to 20 (it’s not critical for me).
Tell me something if you can.
Thanks in advance.