WiFi greyed out and won’t turn on and Ethernet also doesn’t seem to work

Here is how I suggest you do a clean install:

1) VERY IMPORTANT - BACKUP! You are about to erase your system drive. Never do that without a backup - well, actually, you should have at least two... I recommend a Time Machine on one drive, and a full clone of your system drive in a separate one.

2) Download the full  Big Sur installer from the App Store. If the installer starts automatically, quit it.

[if the OS you want to install is an older one, like Catalina, Mojave or High Sierra, use this link instead: https://support.apple.com/en-us/HT211683]

3) Create an installer drive on a thumb drive, following the instructions here:

How to create a bootable installer for macOS - Apple Supportsupport.apple.com › en-us

4) On recent macs, you may need to authorize booting from an external drive, which may be disabled by default. You do this in "Boot Security Utility".

Information about this is available in this support document:

https://support.apple.com/en-us/HT208198

---- do not proceed further without a backup!!!! ---- 

5) Restart your mac holding the Option key, and select that installer disk to boot your mac

6) Use Disk Utility to reformat your internal drive as APFS

7) Quit Disk Utility and start the installer. 

8) When asked, choose to migrate content from "another mac, time machine or drive".

IMPORTANT: elect to migrate ONLY user accounts; NOT applications, settings or other files

Reset the NVRAM and SMC.

Restart in Safe Mode and see if you can use Wifi or Ethernet.

In System Preferences->Network, create a new Location and see if you can access Wifi and Ethernet using this Location.

First, you have not just one but TWO third party antivirus. The correct number is zero. Your mac does not need them, they degrade performance, conflict with system security and, in this case, with each other.

It is also obvious from the report that this mac’s OS has been upgraded in place for many years. It has extensions and pref panes that were discontinued years ago.

I strongly recommend that you make sure to have solid backups, then erase and install Catalina. Finally, migrate ONLY the user accounts and nothing else.

I can post detailed instructions a little later, as I am not at my mac right now.

Please run Etrecheck and post its full report here. Use the "additional text" button, as the report is too long to post directly in the message.

Smartmart wrote:

This is interesting. I did as you suggested and in safe mode neither of the old locations worked so created a but new Ethernet one which did. WiFi wasn’t even an option to choose for new locations. I rebooted and the Ethernet now appears to be working fine. I also then had the option to create a new WiFi location. I did, renewed the DHCP lease because it said my Mac didn’t have an ip and then the WiFi worked....for just 1 minute, then it greyed out again and disconnected.

I checked again in safe mode and rebooted but now the WiFi isn’t an option to create as a location in either modes.

The Ethernet is working again however in both modes and has been stable for the past hour so a partial success.

By your description, you migrated everything, and then deleted stuff.

You should have instead migrated ONLY the user accounts and no applications, settings or "other files".

This would have left you with a clean system, with no trace of those "antivirus"... I'm going to guess that one of the things you used to have on this mac was a **** called "cleanmymac"... If that is the case, you really are going to need a clean install.