Probably just me mis-understanding (again!) - see screenshot below:

I just tried to ‘thumbsup’ Jay’s reply. But when you click the react icon, the toolbar opens way over on the left. If you move the mouse pointer off the react icon, the toolbar disappears. However, if you’re very fast and can accurately move the mouse pointer to where the toolbar was (and remember at this point you can no longer see where it was), then the toolbar will re-appear and you can select reactions. Equally, if you’re too slow in getting the mouse there, the toolbar remains hidden. In this context ‘fast’ means flippin quick and ‘too slow’ means normal speed (to me at least)!

I suspect that the reactions are an add-on? If so how to raise this issue with the developer?

Also, are there more reaction that can be added to this reaction toolbar (or has someone reduced the set available)?