If you look to the middle row - SW Playback Channel PH11/12 - there is no audio signal.
So PC/DAW do not seem to send audio to PH11/12.
Then it's no wonder, that you do not hear anything if you raise the fader of SW Playback 11/12 for HW Output Ph11/12.

Maybe it's not fully clear to you, that TM FX adds an additional Layer between PC/Application and HW Outputs on your recording interface. If the application sends audio, e.g. to PH11/12, it will not be send directly to the HW output on your UFX+, instead of this audio 1st appears in the middle row of TM FX, SW Playback Channel PH11/12.

The strength of this concept is, that it allows you to create an individual submix for each of the HW outputs by adding audio from
- HW Inputs on your UFX+ (TM FX top row) with near zero latency
- SW Playback Channels from PC/Applications (TM FX middle row) with the typical RTL (round trip latency over USB3/TB)

Coming back to your picture. I see you have audio signals on SW Playback Channels AN1/2 - AN 7/8, so the PC/DAW sends audio to AN 1/2 - AN 7/8. This you can route to your phones output.
1. Stay in submix mode, its a very comfortably mode for routing audio.
2. Keep your Phones 11/12 HW output selected.
3. Now raise the faders of SW Playback Channel AN 1/2-7/8 as you need
    You can even add audio from the HW inputs to the submix with near zero latency .. as you like/need.

A little more background information:

For this reason every "HW output" is sometimes also referred to as a "submix".
Thus a recording interfaces has as many submixes as it has HW outputs.

Hence the name for this routing mode "submix mode" as you click on a HW output (aka "submix") and then create the submix by raising the faders of HW inputs and SW playback channels.

There are also other modes available for performing routing (free mode, the matrix) but I recommend you to stay with submix mode, IMHO this is the easiest to work with for the usual tasks ...
You can even disable TM FX routing capabilities and enter the so called "DAW mode" which allows you to perform routing within the DAW. I can not really recommend this, because you loose a lot of features and the possibility to route audio in near-realtime directly at the device from HW input to HW output. Then every audio stream has the RTL as everything has to go though USB3/TB.

BTW .. in submix mode you see the name of the selected HW output - in your case/picture PH11/12 - at the bottom of every HW Input and SW playback channel. This is a clear indication that you work in Submix mode and that you selected the submix for HW output PH11/12.

Tip: as your recording interface has many channels .. to make it easier to identify HW Inputs and SW playback channels that play an active role for a submix you can toggle the button "Sub". If Sub is activated then TM FX shows only the active channels for the submix.

I hope this answers your question, if you have additional questions, feel free to ask.

So... magically after rebooting the computer this morning, it is now working... (without any changes...) is this a malfunction in the RME drivers, hardware, daw or coreaudio??? I'm lost..