well. this is not connection issue, but resend unsend messages. i disabled it.
many peoples blamed nightly builds because it resending all old unsend messages from first day of wazapp usage (because original wazapp have bug in resending, and not doing it, but who cares?)
yes, you should resend messages manually in nighly20.

so, should i return resend unsend messages feature to nightly and all new nightly users would get tons of unsend messages will be send at one moment after wazapp nightly starts, but you will get all messages resend when connection switches??