grub can't see Windows 10

The other day I put an SSD-shnik on my computer. Since I use Windows for Il-2 and similar purposes, I decided to place Windows on the SSD-shnik. And as the main OS I have Fedora-32.

Previously, when booting, grub gave out a menu that had both Linux and Windows. But right now I can't update the menu, as os-prober doesn't see Windows. Like this:

$ sudo os-prober
[sudo] пароль для lary: 
$

And that's it... :-(

I tried to explicitly register the menu item in the file /etc/grub.d/40_custom but it ended badly - the menu disappeared altogether! During boot, instead of the menu, a line starting with Error pops up (which I don't have time to read) and Linux loads.

In this regard, the second question is - how can I see the log of grub? After all, when it works, the file systems are not mounted yet!