Hot swap drives no longer mount RW to user. Previously a hot swap hard drive would mount magically through KDE to /run/media/mygreatuser/123-uuid-abc/ and be RW for the user. Now a drive is mounted with root ownership and just read-only for the user.
You say “a drive”. Does that mean that the difference of your experience maybe due to the difference of the devices/ Maybe the difference of the file systems on the devices?
Or is it the same mass-storage device (with the same type of the file systems).that is mounted in a different way today compared to yesterday?
What is the file system type?
Remark that when this is a non-Linux type, it may be that it was used on a non-Linux (e.g. MS Windows) system in between and not removed properly there. Then it will indeed be mounted read-only by your Linux system.
On both cases information from the system may help. E.g. (as root):
I think I have figured it out. The solution was simply to mount the drive and then change its permissions.
I was working with some newly formatted drives (XFS format) for archiving some large projects. Their default ownership was root:root. That may have been the way the YaST Partioner creates drives all along; I don’t remember. Maybe I had to change the permissions on my other archive drives before; I also don’t remember.