Gigabit verizon here.
They rolled out SON (Self Optimized Network) just before xmas, which is what I believe your tech is alluding to.
It is converting the 2.4 & 5 ghz “channels” (SSIDs really, channels is another animal) into a single SSID & adopting single password access.
here I can turn it off.
Which is a good thing, since I already configured the network that way.
When they rolled it out, supposedly off by default, it wasnt & mucked up everything.
Now while figuring this all out, a tech I called to bounce the ONT (fiber to lan/coax interface) from their end, suggested in the course of troubleshooting, & looking at signal strengths to the 60+ devices I am running suggested upgrading to their new gigabit router w IP6, or adding a paired range extender to the existing router (I bought my router instead of renting from them, pays for itself in 18 months).
I figured if the new extender (and WAP addition, both literally just added 48 hours before) didnt do the job, I would consider this alternate route.
Seriously considering it, but in the meanwhile adding 2 extenders (Technically, 1 is a WAP (wireless access point) has resolved any connection issues.
Nearly all extenders are half duplex.
Just keep in mind if you do go the extender route, you lose 1/2 the thru-put on devices connected via extenders.