Default file manager not working + "empty files" when uploaded via web browser

Did a total wipe of my computer (Zorin 16.3 Pro) to install Zorin 17 (regular, not pro) - and now the file manage won't open, seems like a process is getting stuck, and computer is overheating.
Something called gvfsd-trash is #1 on CPU usage persistently. kioworker is #1 on ram usage - on 16.3 gnome/vivaldi were competing for that place. Don't know if either of these are causing issues - not sure how to check.

Also installed dolphin - that opens, and can open files no problem. Default files refuses to open.

So that means that if I download something from Vivaldi, everything freezes and have to force shutdown.

When uploading something into, for example, Google Drive via drag and drop into the browser, from Dolphin - the browser thinks it's an empty file.

I'm not sure where the issue is or how to troubleshoot. Help would be greatly appreciated, thank you in advance.

I assume by "regular" you mean Core edition of ZorinOS 17.
Did you check the SHA256 checksum of your downloaded .iso matches the published value on Zorin website?

The "Files" manager on Core (gnome desktop) is Nautilus. You could try re-installing that.

sudo apt reinstall nautilus