This issue is still relevant in the latest RC (v114.2-rc)
At first it was just tabs not being registered as closed (or opened) as seen in the picture in https://orionfeedback.org/d/2248/1. But other than that, no older tabs were respawning.
This means you only faced an issue when you reopened the tab group later on (all those "31" tabs would open up)
But after using it for a few hours, the tab respawning has also started (Rather aggressively) [as seen in https://orionfeedback.org/d/2248/2]
For now, I have moved only the relevant tabs to a new tab group and it seems to be in the first condition (Tabs not updating properly in drop-down, but no respawning)
This makes me wonder if the main issue is tabs not being actively updated in sync and then something suddenly "triggering" the respawning, after which it respawns way too much (one previously closed tab can reopen 2-3 copies of it and closing the respawned tabs more often than not just spawns back a copy or two of it again)