External hard drive partition improperly recognized as Time Machine

MacBook Pro 2023 laptop running Sonoma 14.7.

Western Digital "My Passport for Mac" 2TB external drive. Partitioned into 2, half for Time Machine for this laptop, and half as general file storage for old files I don't want cluttering up and filling the smaller drive in the laptop.

Issue: Mounted the external drive yesterday to use the general storage partition for the first time in awhile (otherwise drive works fine for weekly TM backups), and it showed no files at all in the Finder window. Looking more closely, the Finder window had a note "No completed backups" with a little button stating "Open Time Machine settings". The disk icon also was a green TM symbol, not the expected orange general drive icon. In the Time Machine control panel, only the expected drive partition showed up in the drive list, but if I click the "+" to add a drive, the other partition is listed as available and in green as a TM drive. I clicked "remove" and that partition drops off list, but the mounted (or remounted) drive remains a TM icon on the desktop with no files in the Finder window. In Disk Utility, this partition shows 600k+ files taking up 200+ MB, so the files are there, but somehow the disk partition now thinks its a TM drive? I certainly never told my laptop to use that partition as TM. I'm guessing the Finder won't show me the files that still seem to be present in that partition as they are not TM backups?

Question: How do I tell a drive partition to stop trying to be a TM disk so it shows me the files it already has on it? Must I reformat, or is there a less aggressive method? I do have another copy of nearly everything on that partition on another external drive, but not everything (I know, I know), so is there a way to actually see these files to compare/copy to my other drive before any reformatting?

Thanks!