Once Official software its released is going to be smooth as any other Official release, if you're going to be bashing the developers work maybe this program is not for you, just withdraw from the Beta program and install the Official Android 10 software 🤷
Even I have this same problem with T-Mobile network while on Official Android 10, I own the S20 Ultra unlocked and was loosing signal or getting calls dropped very often and the more annoying problem was when my phone was reading 5G but in reality I wasn't connected to any network
until finally corrected the problems, one problem was my SIM card as I was using the same SIM card for years and phone was not properly switching to 5G specially if the signal was not strong, T-Mobile released a new card stamped R15 for standalone 5G, other problem was that the APN that my phone was set up with the old SIM card was totally different to the one T-Mobile provided to me , after installing the R15 SIM card and with the new APN I have to reset the network on my phone to erase all the previous network data and since that date I haven't had any issues with the network "specially" when my phone is switching to 5G.
One way that you can check if its your carrier network is by turning the 5G off, if you get better signal without the 5G then your problem is within your carrier network.
This is one of the reasons why the "Beta Moderators" are telling you that its a carrier issue.
Hello @SCRAMJONES ,
Our software is tested extensively before it is released to consumers. Any software with critical issue such as data connectivity would not be approved by our QA team for even submission to carrier. In regards to network issues, There have been fixes required both from our end as well as carriers during beta program. Also note that same behaviour of device such as a network loss could have multiple reasons and may be different for each user. If you still experience connectivity issue, please send us an error report as soon as you experience the issue.
One Ui Beta Team