iPhone Hot Spot, devices won't connect

Can anyone please help me understand why the personal hot spot on my iphone 13 is so useless? It will connect ok, but then when I leave for long enough for the mac book to go to sleep it will never reconnect. and now the only way I can reconnect to the hot spot is to reboot my mac book and the phone. Surely this isn't right?? I never had any issues when I had my samsung phone and using that as a hot spot, it always stayed on Please help... thanks. Iphone is Pro Max 13 on iOS 15.5 and mac is MacBook Pro (Retina, 13-inch, Mid 2014), Big Sur 11.6.6 but mac is irrelevant as it only has this problem with the phone. I have tried to reset network but this causes too many problems like losing all Bluetooth and network connections and did not fix this issue.

Image below shows connected to hot spot but not getting an IP Address