This worked fine for me...

Looks like a Altsound Soundset, this is buggy in RC9 as far as I know....

Is your DAC Module connect with all pins to the main board ? If so, thats wrong and connect it like on the TiltAudio Website described.
The Output device is Hifi DAC or equal-dac for example...

https://tiltaudio.com/2019/04/09/assembly-instructions-for-2-5b-blue/

look at "wire for DAC" pic

I hope that helps, i had that once...

kba78
i looked at your board pic and found the 40pin socket complete down to the board. The socket is having long pins to allow an easy plugin for the rasp, so how did you mount the rasp to the socket/board ? Did you bent it somehow ? Maybe here is the problem and that why it worked just for a while ?

in V1.29, disable LUA in the config and the Key request disapears as the old Key is not including the LUA feature...

Hi,
check and meassure the 5V on the board..
I can not see your DAC converter U5 by the way, this one is necesarry to connect between RasPI and Amplifiers

OK, insert the U5 and check the Web UI for "enable_minidisplay" in the config screen...

Ordered ?
It is normally part of the standard. To prevent misunderstanding, U5a is a extra option DSP Modul, U5 is the smaller DAC and standard as far as i know...
So check the package, it should be in. In the meantime, connect a standard headphone to the 3,5mm socket direct at the Pi itself and change the output device accordingly in the Web UI

AAhhh.. OK

Display now Ok ?
so it works when the DAC is in...

HI, to change the sound output from the headphones to the DAC, you need to change the Audio device in the Web UI to equal-dac !