Well, maybe it is working normally then. Still, it's too annoying to be my everyday meter so I've boxed it up and the seller is going to refund my money. I don't really want to unbox it to do a video. I now have $110 Paypal credit, what should I buy? I'm thinking the EEVBlog/Brymen but if you think there's something better in the $100 - $125 range, let me know. Oh, and where can I find your spreadsheet? Thanks for your help.
Hard to say. You have a UT139C but "want a high quality meter as my primary". But you went from 6000 counts to 4000 and an TRMS meter to averaging. You even had NCV that you gave up with the Fluke. You can see why I don't recommend meters. I would really have no way of knowing what you need/want beyond the things you mention being a concern with the 17B+.
If the 139C does what you need, just stick with it. Save up your money until you find something you actually need or want. I'll continue to use my old Mastech in the garage till it starts having problems.
Overall, for electronics work I still like the BM869s as a general purpose meter. I'm also liking the old 189 that my friend gave to me. The more electrically robust brands (assuming that metric would have something to do with quality) are Brymen, HIOKI, Fluke and maybe Gossen. The Fluke 87V seems to be a bit of a flyer but every other meter I looked at from them were very solid. I was not impressed with Gossen from a service or product standpoint. The meter I bought has way too many problems. Still, from my tests it's right there with the best of them. It's just not a well thought out meter. You could have a look at Keysight. The one I tested did not hold up near as well as I would have expected. It was a new design, not like the antique 87Vs so really no excuse IMO for this brand to have done so poorly.
If you just want something with a very fast non-latching continuity test, some of the meters like the UNI-T UT90A can handle over 10KHz. Some people like the latching. For me, I like the non latch for the feedback and speed for electronics. In the garage or basic electrical work, I could care less.
Anyway, hope that give you some idea on my view. Download and read the manual before you buy. If you have questions, ask first. If there is something you want demonstrated, I would ask. Chances are someone will have the meter you are looking at and have a camera.
If you click the link in my signature and select about or discussions you will find the link to the spreadsheet. It's also in the very first post of that long thread.