I will submit logs and anything else I can to provide a solution, soon.

See if you have any mod that affects the rendering of signs, such as enhanced-block-entities or similar. If you don't, ensure you're putting the right data into your sign. Try this, for example:

[row 1] !PS:imgur:
[row 2] Vbwkq2b.jpg
[row 3]
[row 4] 1:1.2:0:0:0

See if you have any mod that affects the rendering of signs, such as enhanced-block-entities or similar.

Yeah I run Enhanced Block Entities, although I can just turn off signs in the config, perhaps you could do a compatibility update that either makes it possible or straight up turns off signs in that mod? (Or just add it to the description as a note)