These are indeed 2 very good videos which I can only recommend to watch, Waldemar.
Its a very good alternative compared to "dry" handbook reading.
Totalmix FX is the latest Mixer technology, which all new products use now, really nothing Beta.
I am using it together with the UFX.
BTW .. Its regarded as very nice from RME to make it available also for older devices, see Website in regards to "Totalmix FX 4 all".
Other companies would have spend no efforts in such initiatives to backport something new to devices up to 10 years old.
This is the value of buying RME, that they spend i.e. such efforts and fix bugs etc.
BTW .. to be precise, the Effects of Totalmix FX you can only get on devices which have a DSP for effects built-in.
But you benefit from a) the facelift and b) any new functionality of Totalmix FX vs the older version.
Either something went wrong in regards to your Midi problems, which can happen along such transition to new driver/mixer or you need to use it in a slightly different way.
And something like going back to older drivers should still be an option for you, shall you you be not prepared for such changes at the moment.
BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14