Hello @sneaker-net, thanks for your valuable feedback !
You are right, I confirm that the “Last logged in” is updated when the user hit “Sign-In”.
AFAIK, I don’t think there is any workaround for that. I have created an internal ticket for this (ref. PB-35324) in order to potentially investigate what could be the reason behind that.
Regarding the investigation and a potential implementation, I can’t give any ETA since it doesn’t seem like a blocker, so I am not sure if it will be tackle anytime soon by development team as they are currently working on the v5 (if you haven’t been teased yet 
) but if we have more information about it or if there is any workaround we will let you know! 
Thanks again.
Best regards