Clicking 'Quote selected' link has no result

0. Try to clear drupal cache
1. Try to disable JS aggregation
2. Try to disable BigPipe module

Try every way in turn

BigPipe is already off. I stopped using that a while back due to some other problems it was causing.
Drupal Cache: Cleared. I do this frequently when updating, but just did it again.
JS aggregation disabled: Did that.

There was no change in results.

Update: I tested on another site that has very few contrib modules. Quote is working fine there, so I must have a module conflict of some sort. I will need to free up some time to figure it out.