Hello *******, I am have been for sometime in the same boat concerning WiFI Catalina. Issues that have been spoken of in many online posts throughout the Internet. I have tried everything from replacing Airport card (WiFi/BT), checking wire connection to it, plist rebuilds, inactivating WiFi service and reactivating deleting Wifi creating a different location,MTU set, renew DHCP and then some without success if not for a momentary erratic and short-lived WifI connection that went from a few minutes to a few days (yes weird)... This in addition to the iGPU problem. I have finally given up and bought the last MBP, a 2012 non-retina with user ability to both upgrade drive and Memory where I can transfer my existing SSD and 16 GB Men to continue my work while eventually jumping in time to a newer 2022 MBP (see my post below). Of course this MBP may also find itself afoul of the Wifi issue but seems successfully solvable overall, much less of an issue and much much more prevalent of a problem with the MBP 2011 models. I know this doesn't help your current situation but you can alway use your ethernet connection that always works although forcing you to tether or reverting back to High Sierra that has hasn't seen the issue but perhaps with its limitations in fonction of what you need to do with your MBP. Other than that Catalina with Dosdude Patcher works seamlessly and very smoothly and a joy to use. Best of luck.