Okay. But the screen does get initialized? A e.g. Lenovo Logo is displayed, before Grub starts "blind"? If so, and if grub worked fine until the last change, then I presume, that your (/boot/grub/)grub.cfg file makes trouble. [As soon as it works again, I would save a copy of that file somewhere
.]
I did append my version of grub.cfg - renamed as grub.cfg.txt to be able to attach it. There, I just cut the "30_os-prober"-section down to the MS-Windows-entry. Of course, all the entries concerning "disk-values" (like label, UUIDs, partitions etc.) have to be adjusted.
I suspect the "else"-branch of the "load_video" function, which is responsible for UEFI-display-handling to be the culprit part.
You can also start any (working/displaying) grub - e.g. from ventoy or whatever -, then press 'c' for command mode and then run "your" grub-configuration with 'configfile "diskpartition"/path/to/configfile/grub.cfg'.