Same issue here: Seed -769377605413661384 at 300 90 950 (Minecraft 1.18.1)
when you press the button it fires one time, but when you press it again it doesn't, so this is another bug. Also the dispenser is directly powered.
you can see some arrwos moved.
There is a change that can be made to the text shader that remedies this issue.
You can check out the code here. It is based on this video which goes into the details of how it works.
Note that this algorithm requires bilinear filtering to be enabled in the TextureStateShard for the "text" RenderType.