It seems that Right Clicks trigger twice in Firefox for both All Links Clicks as well as All Elements Clicks

This can be reproduced with the following:
Setup an All Links Click or All Elements Click trigger (It's easier without any filters)

Setup a tag to send an event to Matomo

Open the page in a browser tab and right click any link on the page - to be 100% sure, don't click anything else in the page at all during the visit.

Check the Matomo Visits Log:

The exact same steps performed in Chromium do not have the same issue:

In the example above I have a pageview tag that sends a test event each time a page loads (Pageview trigger). The other two events are All Links Click and All Elements Click triggers.

Current Matomo version: 4.6.0-b2

This was originally reported from a Matomo Cloud user.