iPhone, hizmet 'çubukları' yerine noktalar gösteriyor

Hi... my wife and I have iPhone 12 pro and our service is provided through Spectrum which uses Verizon lines (both Verizon and Spectrum said so). Anyway, the phones make wi-fi calls but sometimes we see 4 dots instead of any 'reception/service' indicator bar in the upper right corner of the screen... next to the wi-fi indicator. When this happens, we cannot send or receive texts or phone calls. Now we thought it was a Spectrum issue and we've been messing around with them and they do all sorts of 'procedures' on phones (and have to put things back every time) and it still happens. So they obviously have no idea. BUT...our daughter and son-in-law recently purchased iPhone 12 Max phones through VERIZON and are having the same issue.
We (both Verizon and Spectrum) were told to put it in airplane mode for a few minutes and then toggle it back so it could reconnect to the network, and we were also told to pull out the sim for a few minutes and put it back. so it can reconnect... and it works for a short while, but again, nothing works to alleviate this problem.
Anyone else having this same problem? Can anyone provide any help or solution? It's too much to pay for a phone when it doesn't work that often. Basically, HELP.
Thanks for listening.
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