Press F11?
This is extremely annoying. It is definitely a result of MC-75630. I don't care if you need to make a new block to dispense command blocks, but something needs to be done to fix this. One does not simply introduce a feature, let the users use it for almost a year, and then remove it.
Sorry everyone, didn't realize this was working as intended. Never used a "true" argument in NBT before.
Can confirm in 1.20.4