Safe Mode Boot Issues - MacBook Air 2019 Sonoma

I'm trying to boot my 2019 MacBook Air running Sonoma into Safe Mode.

I can successfully boot using the shift key but run into issues once the login screen appears.

Basically the login screen appears briefly, the screen then goes black, the cursor then appears in the top left of the screen and then the login screen appears briefly again and this cycle restarts.

Whilst the login screen is briefly visible (1-1.5 secs) the keyboard and mouse work. I can get a few characters of the login password in before the above cycle starts and then when the login screen reappears the password field is blank again. This cycle never stops.

I have changed the login password to a single character and successfully 'logged in' but once the system leaves the login screen the cycle starts again but instead of the login screen there is just a black screen. This boot never finishes and continues to cycle.

Powering thew MacBook off and on again allows it to boot correctly into normal, non safe boot, mode.

I have completely reinstalled the system from a network recovery. Once I create the default administrator and get the system functioning after a basic setup, the safe boot successfully works. This is with a single user on the system.

If I then proceed to create a standard user and install apps and use the MacBook Air for a while then try the safe boot this is when the safe mode boot cycle issues start.

I have no idea why I would suddenly be facing these issues but any help to diagnose and fix would be greatly appreciated.