Delay between profile being in Avoid Me and my Xbox saying I'm in Avoid Me?

Rep is nothing to do with support.

You can find out about the rep system & how it works
here

It sometimes takes the enforcement site a while to sync up.Your rep on your console is your true rep.

I'm in a similar situation. I had checked the enforcement page after playing many multiplayer matches and I said I was a good player. Then I went on xbox one and it said my profile was in avoid me. Then I got back to the enforcement page and it says I'm
in avoid me. It is a bug that you are in. To try to get you rep up, try to join someone's game from you recent player list. This might work. This glitch has something to do with your profile on the enforcement page not being in sync with your profile on the
xbox one. Also, it might have to do with the message that xbox sends you saying that your rep has fallen to avoid me or needs work. This message might trigger your rep to go down even if it should go up. This message should expire 1 month after you receive
it. I hope Xbox fixes this bug

For information about how the rep system works and how to improve your rep can be found here - http://enforcement.xbox.com/home/howto#sub-topic0-0

I have already checked to see what my rep is, and I have no "Avoid Me" notices on my profile, my reputation on the XBox Live profile page shows I'm in the Green and other than an enforcement notice over my GT I have no messages saying I'm a bad player yet
people are being told to avoid me when joining my club on Forza Horizon 3.

Yeah,it sometimes takes the enforcement site time to sync up properly.

Whatever your rep says on your console is your true rep.

You can find out about the rep system
here

Player reputation is separate from an enforcement action.

Player reputation changes when your have received negative reviews on your Gamertag.

The enforcement page is to see your account may have a suspension.

Alternatively if it says good player, it may have not updated on the site yet either as well.