I also had this experience starting with 17.2 ios
ipad mini, MacBook Air and 2 iPhone SEs would randomly drop the wifi after a variable but frustratingly short period. The wifi said it was connected but no new sockets would open. Turning wifi off then on would resolve it but sometimes took 4 or 5 attempts. Made the product unusable… and upgrade would require a wired connection. For people affected this is extremely frustrating.
They had all been working previously to 17.2 in the same environment with no problem. Upgrades to 17.2.1 and 17.3 made minimal difference.
When travelling though I noticed the problem did not happen on hotel wifi so it was likely some compatibility issue between my actiontec router and more recent iOS.
I solved the problem by using the channel steering feature on the router to force my devices to the 5GHz band. They now work pretty well with few disconnects.
It seems like changing bands or something specific to 2.4G band is the problem area. Please take this seriously Apple.