[Outage 08/18/2022] Saving not working

I’m suddenly unable to merge duplicate tasks, is this related to the connected work links update?

Example:
the option to merge duplicate tasks only appears when I have more than 1 task selected in My Tasks (or the relevant project) but I’m unable to choose the name of one of the selected tasks to merge into. The result I guess is that you can only merge 2 selected tasks into a 3rd task, not merge one selected task into another one.

edit - the 1st task I was selecting was a Milestone. Are we not allowed to merge 2 milestone tasks?