AFIK, TM is working. I just tested it by restoring from the a file that had not been altered (so nothing had changed). Do you advise reformatting and creating a TM backup from scratch? That's the only other option that I can see.
Honestly, I've dealt with a few dozen time machine backup drives that were having issues, and the best thing I can suggest is nuke it and start over. Those volumes just weren't intended to be repaired, there's a metric crapton of hard links on them and it just overruns any tool you try to use on them. When it comes time to retire a TM drive for whatever reason, I usually just unplug it and stick it on the shelf and get another one. Storage is cheap, and that way I have an old archival backup in the unlikely event I need to dig up something really old. That's what I'd suggest you do, shelve the drive that's giving you issues, and start over. Your new drive will be faster, bigger, younger, and known good, plus you'll have that archival backup in the closet (or offsite, even better!) in case you need it.
(a thunderbolt SSD TM drive for your mac with the SSD in it... is a beautiful thing)
