“Please run ‘e2fsck -f /dev/nvme0n1p7’ first” when trying to resize partition using GParted
It has to do with the timezone of your system. GParted live, for instance, boots with UTC timezone.
If you are in GMT+something timezone, then the last time the partition was mounted is in the future. Therefore, running e2fsck does not update the date that resize2fs is checking to insure that the partition was checked.
Setting a date in the future, or waiting for a day, will be sufficient to resolve this issue.
I had the same problem as you, and your update gave me the idea to try that.