Having issue with high background noise that seems to depend on other LEDS/screens in other modules

[Testbild-synth]

so I've built the module half a year ago and but haven't tested it extensively or even calibrated it really. Now today I set up a new rack and tested everything. On my unit, there seems to be an issue with very noticeable background noise that seems to depend on the other modules connected to the same PSU/near it. Specifically, when I unplug modules with oled screens and modules that have many LEDs, the background noise is considerably less.
I never noticed this in my old rack, might have been there already though since I didn't get to use the module much until now.
Do you think this could be caused by the power supply being strained (my new rack has a relatively small PSU for it's size), some RF thing or the tuning/calibration of the unit?

[lookitsgraphic]

This is not necessarily due to the power supply, in the event of an undersized power supply, certain modules risk freezing or showing other symptoms.
On the other hand, many modules using tubes capture the noise of modules using I2C OLED screens and LED displays. The best is to put the digital modules on one power supply and the digital modules on another.