I figured older firmwares could be obtained from Mikrotik download area with manually changed version in the very end: v2.4 - https://download2.mikrotik.com/swos2/css106/swos-css1061g4p1s-2.4.bin v2.5 - https://download2.mikrotik.com/swos2/css106/swos-css1061g4p1s-2.5.bin v2.6 - https://download2.m...

That's interesting, but looks like 2.6 release broke IPTV functionality for me.

Just upgraded to 2.6 from 2.4, now IPTV is broken through CSS326-24G-2S+. Multicast stops and starts continuosly.
Where can I find 2.4 image? I would like to downgrade.

Thanks!