If you have an older laptop and don't have anything newer to test, spin up a decent VM in azure and edit the flow from that VM. Before I upgraded my laptop, that's how I edited complex flows and Power Apps forms, due to to the significant performance difference between my older laptop and the Azure VM. (if you don't have access to azure, search for "azure dev essentials" for a free program from MS that provides a certain amount of free credits to try).