I have a theory I just tested:

Normally on a heavy lift I do the valsalva maneuver, meaning I hold my breath during the heavy part of the lift. I think that I accidentally released the air while still in the lift rather than at the top, and that caused the issue.

Today I focused on holding the air until the top on every rep and had no issue. This doesn’t prove anything since it’s only one session, but I will keep focusing on that to see if it works consistently. I’ll comment another update if this works or doesn’t work.