Wifi Connection Failed after upgrade

[EPR]

So I'm running into an issue now after the Catalina update where my wifi will connect for about 15 seconds at a time then disconnect and re-connect until it finally says wifi connection failed and asks for me to enter my password. I am able to reconnect for 15 seconds at a time if I either close this and choose my wifi ap again or just type in the password. It does connect to the internet but it will not stay connected for longer than 15 seconds or so before disconnecting. This happens when I hotspot off my phone as well but it lasts maybe 20-30 seconds longer before a pop up shows where I need to hit join. I am not entire certain what is going on here but I looked at my sys info and this is what is under wifi

Software Versions:
CoreWLAN: 13.0 ((null))
CoreWLANKit: 13.0 ((null))
Menu Extra: 13.0 ((null))
System Information: 12.0 (1355)
IO80211 Family: 12.0 (1200.12.2b1)
Diagnostics: 1.0 (910)
AirPort Utility: Not Installed
Interfaces:

en0:
Card Type: AirPort Extreme (0x14E4, 0x159)
Firmware Version: Broadcom BCM43xx 1.0 (7.77.106.3 AirPortDriverBrcmNIC-1440.1)
MAC Address: xx:xx:xx:xx:xx (edited)
Locale: FCC
Country Code: US
Supported PHY Modes: 802.11 a/b/g/n/ac
Supported Channels: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 36, 40, 44, 48, 52, 56, 60, 64, 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140, 144, 149, 153, 157, 161, 165
Wake On Wireless: Supported
AirDrop: Supported
AirDrop Channel: 149
Auto Unlock: Supported
Status: Not Associated

Im not sure why the software version says null and there's now no airport utility installed. I am assuming something didn't go smoothly with the Catalina update. What steps can I take without having to reformat and reinstall everything?

 

[Average Pro]

Same issue here (MacPro 2013). I just completed the upgrade to Catalina, had access to the internet, via wifi and then it stopped. Following a reboot, I have access to the internet for a few seconds and then it stops. I have a MacBook Pro and other Apple products which are connected to the wifi and work perfectly fine. So far I have:
(1) restarted
(2) turned off, unplugged, waited 1 minute and restarted
(3) deleted and then renamed wifi under network settings
(4) Safe Mode
(5) reinstalled Catalina again
(6) restarted my modem and router
(7) created a new log-in ID
(8) renewed DHCP Lease
(9) cannot connect via ethernet cable
(10) cannot connect via Personal Hotspot. The window to join appears on the screen, but it never connects. After a while, the window to join appears again.
(11) NOTE for #9 and #10, it show that it is connected to the internet under Systems Preferences

Prior to reinstalling the OS the 2nd time, utilizing Command-R, I had access to the internet via the "Get Help Online" option. Here I could go to any website and it worked. However, the problem returned after the install finished.

I am now in the process of installing a completely new OS (erased my disk). I will provide an update.

 

[Average Pro]

Fixed. As of late last night, no problems connecting to the wifi.

 

[Taz Mangus]

Fixed. As of late last night, no problems connecting to the wifi.

This might be helpful to other posters, what did you do to fix the issue?

 

[Average Pro]

I did a complete reinstall by first erasing the disk. In short a completely new installation.