Problems with incoming SIPNET calls on Gigaset C610A IP phone and MIKROTIK router?

Question

SIP

There was a problem with IP-telephony on the Gigaset C610A IP phone with the SIPNET operator, outgoing from it passes, but incoming does not come. With other operators Multifon, Central Telegraph (gobaza.ru), Beeline, everything works in both directions, both incoming and outgoing.
in the SIPNET personal account, the connected device is seen as follows: SMNS096***@128.69.***.***:60277/tcp C610A IP/42.076.00.000.000 i.e. The IP address is external, not internal network 192.168.88.240. I think it is necessary to prescribe in the router settings either port forwarding or something like that.
Internet provider Beeline with their VPN connection. Router MikroTik RB951G-2HnD.
I would be grateful for any help in solving the problem, at least direct me in which direction to look.

Answer 1

www.mikrotik.by/index.php?s=9a1418512fd3428e32f56e...
or
www.dslreports.com/forum/remark,23880773 (lowest answer)

Answer 2

so look at what traffic goes to the router and allow it to pass.

Answer 3

IP->Firewall->Service Ports->SIP->Disable
first disable SIP-ALG in Mikrotik.