When I try to use the 192.168.1.1 (Sunrise Internet box) as DNS server, i.e. the default config, it no longer resolves SRV records - it used to until a week or so ago.
Can’t connect my softphone. If I set my DNS servers manually to use 22.214.171.124 & 126.96.36.199, everything works fine.
It seems that your DNS servers 188.8.131.52 and 184.108.40.206 (which is what my Internet Box is using right now) aren’t quite working right … repeated queries of the form
dig @220.127.116.11 _sips._tcp.MYDOMAIN.ch SRV return NXDOMAIN (i.e. error) and then NOERROR (with the correct result), and then NXDOMAIN again etc.
After perhaps 20 or 30 queries, the servers behind these IPs now seem to be returning the correct result consistently (NOERROR).
(Note - querying the authoritative DNS servers at swizzonic.ch yielded 100% success)