In all the Discourse forums I use I very frequently click the Share button to copy/paste post links in other posts I edit. As forum admin I do a lot of this from mobile using Firefox for Android.
Now it happens that Mozilla decided to completely revamp the UI starting from release v80. Besides that after weeks I still utterly long for the old FF user experience, I just found that the UI affects how the Discourse Share button operates.
It pops up an Actions window that is part of Android UI and contains AFAICS no copy/paste action:
Maybe there’s a workaround, or feature I overlooked, but otherwise maybe a change in Discourse could mitigate this FF ‘feature’.