With firmware versions 18.104.22.168 (and indeed previous versions, but this was the first where the phone didn’t hang after a few hours) and then 22.214.171.124 both work fine, but when I upgrade to 126.96.36.199 or 188.8.131.52 (BETA) then the WP810 never rings and the SIP server eventually returns a 408 (request timeout). If I rollback the firmware to 184.108.40.206 then it works again.
Are others having this issue? Are there likely to be settings that I need to change or is this a bug?
How do I need to proceed to get this fixed?