This has been brought up several times here and a worked solution is buried deeply in hundreds of comments.
Took me half hour to find and solution and wanted to share:
"The trick was from github user julianfairfax comment:
https://github.com/GrapheneOS/os-issue-tracker/issues/2329#issuecomment-2364571618
So I did only discover their solution. 😽
Yes, setting system time a long time into the future temporarily makes the ghost files deleteable. Delete them through stock Files app, it may take a couple of seconds for the ghost files to vanish after telling them to. When gone, return system time:
Settings > System > Date and time > Automatic date and time: ON"
Hope this helps, save your time from installing another files manager, disable/reenable apps, reboot abd etc.
Source: https://discuss.grapheneos.org/d/26473-unable-to-delete-certain-files-file-manager/13
Credit: @Novaliss