Apparently your eyes totally glazed over while reading this part of my OP.....
The latest version has Joomla 6.0.0 baked in and the webhost has yet to update the server to provide for the minimum requirements of J6.
Your team has not deleted other pre-J6 quickstarts, or even pre-J5 quickstarts for that matter, so why suddenly this one!? As with SBBP itself, your team makes some very annoying decisions with regards to the file server that make no sense to anyone other than yourselves!! "Rythm v2.0.1 Quickstart version is currently unavailable" would make perfect sense if it were that I was asking for a new feature but something that was previously available shouldn't simply vanish and then magically cannot be restored!