Can't repair model

SUmodel1.skp (583.6 KB)

Need advice urgently please - job required to be completed immediately.
This model had a few holes. I fixed those holes - and others appeared! I fixed those holes and the first ones I fixed reappeared! Around in circles several times now.
Can someone have a look and see if this happens to them please.

The repaired faces also disappear when the file is saved

See if this works for you.
SUmodel1Box.skp (649.1 KB)

OK, it works and I am eternally grateful - as always - but what is the issue? (Also, I am getting a message saying your file is newer than my SU.)

There is an update available for 2021.

The problem appeared to be that you had scaled the component and when working on it it was confused. There is also some rather rough geometry, probably your repairs.
I exploded the component and repaired half then flipped the other half into place.

The geometry was beautiful - before I mangled it, progressively, in frustration.
Actual size is about 5mm in height, and so I scaled it up a lot to get the round corners to work. I do that often - without issues. But I think I comprehend.
“Exploding” sounds like the key word there.
One would expect to be notified of updates.
Thanks again, I really do appreciate it.

Any chance you have unticked Allow checking for updates in Preferences/General ?
Although it is very recent so may not have been fully pushed yet.