Hello @Kingsboy48,
I switched from HT701 to HT802 few months ago.
Are you using TLS (secure) SIP connection? If no, I would recommend just for the simple reason that it makes things infinitely simpler with NAT and firewalls, etc. There will be only one connection to voip.ms. This might make things more stable.
If you are using TLS, are you sure you did set all the little settings for it to work properly. I got caught up with this problem. It took me a while to figure it out. Make sure to check the wiki page for detailed instructions:
https://wiki.voip.ms/article/Acrobits_Groundwire#Call_Encryption_-_TLS.2FSRTP
Otherwise, it will be a debug process to find out where is the problem with RTP port range, SIP port forward, etc.
Kind regards,
Alexandre