Did you try deleting the connection and adding it back? When you say the phone and laptop will not recognise each other do you mean the hotspot is not visible on the laptop?
Hmm you can try resetting the network setting found under settings / General management or System. If that doesn't work a full reset may be the only option left.
You haven't mentioned what phone it is as an internet search may find other people with the same issue and a possible solution.
Ok my phone is a Samsung Galaxy A50, I have done an update that was requested from Samsung, I have also been into Optus shop and they could not solve my problem, rang Samsung and they could not sort my problem remotely so now I have to return my phone to Samsung for them to do a complete reset, not very happy with this outcome as now I will have no phone for goodness knows how long and as I live in the country this is not a great outcome. I now have to use my husband's phone for our access to hotspot on laptop. We have had nothing but problems since switching to Samsung mobile phones.