After restarting the laptop, the cursor (underscore) sometimes blinks. How to fix it?

Question

GRUB

Hello. Tell me how to fix the problem: I
recently installed Windows 10 (on HDD, installed first) and Ubuntu 20.04 (on SSD, installed second).

Sometimes, after rebooting, I skip the choice of OS from Linux (GRUB, it seems to be called) and instead of it the text input cursor appears (underscore type) and blinks, then it goes down one line even lower (I don’t know if this is important) and then nothing happens . I reboot with the CTRL + ALT + DELETE combination, after which everything loads normally, but if I just reboot from any OS, then the OS selection is skipped again. It seems to alternate. How to fix the problem? Because I sometimes connect to a laptop remotely, and in this case I cannot reboot the laptop (and this is sometimes necessary), because then the laptop will simply remain in the BIOS (and remote access programs work from under the OS).