Swisscom TV works without problems. You have to download the Multicast package from Mikrotik, then configure the IGMP proxy under Routing > IGMP Proxy. Depending on how you have configured my firewall, you also have to allow protocols/ports. The best thing is to ask for help in the Mikrotik forum, they usually answer quickly.

Not all functions are available in swisscom tv without special configuration.

For the time being, I have connected swisscomtv directly to the swisscom router again.
If swisscom tv is connected via the mikrotik RB4011, live tv does not work (but replay does).

I am also interested in finding out how the mikrotik router can be configured for swisscom tv with IGMPV3.

Unfortunately I can't test this, I don't have Swisscom TV, but someone who sold a Zyxel GS1900 specifically mentioned that the GS1900 Midelle can do this. The Zxyel GS1900 switches are managed, with a web interface. I also use them myself.

Zyxel GS1900-8 (8Ports)

The one with 24 ports is great value for money:

Zyxel GS1900-24E v2 (24Ports)

These switches are fanless.