Keepgo Data SIM Failure (Pixel 2)

Suddenly (well, maybe a few months ago -- I rarely use it) I am no longer able to contact google voice via the SIM.  It contacts websites fine, but doesn't connect to google voice at all.  The Keepgo people are responsive and I have followed their instructions regarding the APN, and they haven't given up yet, but to no avail.
I had thought that I used it to make a google voice phone call a few days ago, but it went through our home (or other) wifi rather than the SIM.  Latest google voice update was (I think) June 24 2024.  I know it WAS working earlier in the year because I made calls from my car when there was no wifi hotspot nearby.
Has google voice made some change since March or April that might have created connection problems?  The service was perfectly good at a reasonable price ($30 for 3GB plus $3.00 for another 1MB to keep the unused data rolling over) and I've only used 500MB in a year and would like to keep it.
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Cheers, Bev
   I didn't break it!  It was doing that before I broke it... er...