How to configure Cisco IP Phone 303 under SipUni?

Question

Telephony

The situation is as follows:
There is a Cisco 303 device and accounts in SipUni.com and SipNet.
Sipnet is configured in two counts. But with SIPuni some troubles. I installed SipUni on the first line with the settings:

Everything connects, works, BUT: if I put the call on hold, then I can’t return to it. By pressing the button corresponding to the SipUni line while it is on hold, the call is dropped.
With Sipnet, everything is buzzing: holding, transferring a call, switching between calls. But SipUni does not want to work.
The sipnet settings are the same as those of SipUni, except for NAT and SIP Transport (instead of UDP, sipnet uses TLS).
Demonstration of all this trouble on the video - https://youtu.be/cj06O2fwf9I
I beg your help.

Answer 1

Such a glucodrome should be disassembled together with sipnet support - their logs will tell more than guesswork.

Answer 2

Try translating with an asterisk, for example *100#. The problem here is that instead of short numbers (100, 200, 300), sipuni uses unique logins like 0XXXXX100 for each sip number.