CHIRP

I just bought a new batch of UV-5R2+ radios (3) - My last group (4) were purchased in Nov 2018 from same online vender... all radios are identical as far as I can tell.
Using CHIRP (initially, I used last 2018 build... then updated CHIRP when this issue emerged), I uploaded a blank copy of the radio's memory to my Mac and then cut and pasted my channel build onto what I pulled from the new radio. - I downloaded the updated copy to the new radio. - Then I noticed the PTT button on radio would only "beep".. but not transmit. Strangely, in frequency mode, the transmit button works fine. Radio appears to function perfectly in all other ways. This issue was replicated in all three new radios. - I suspect it might have occurred before I programmed them... but I wasn't looking for a problem, so I'm not 100% on that.
However, I did a factory reset on the radio with the problem (from the radio's menu) after factory reset this problem persisted, then I downloaded the memory of one of my functioning radios (I believe it's identical to the new radio... it was purchased recently) to CHIRP and tried pushing THAT to the new radio. The PTT problem remained. I also tried to push an updated copy of the program to my functioning radio (as an experiment and to update the welcome message on the old radio)... then my old radio (3 months old) began to exhibit the same PTT problem (it has been functioning perfectly until then). - Then I took a functioning radio and compared all available menu settings and with identical menu settings, the problem persisted.
This appears to be a software/programming issue.. but I don't know how to approach it. Is it the newer CHIRP? Is it Baofeng Firmware? Is it Python? or a problem with a recent Mac OS update?... (I've programmed a couple dozen Baofeng radios with no issues.. this is a first for me)