Hi Stevie Jay,
On PC/Mac:
In the lobby click the gear icon and check "mute guests" and "hide muted players".
On mobile:
In the lobby, tap the speech bubble at the top left and check "mute guests".
To hide them, open the "players tab" and check "hide muted players".
To mute specific players (PC/Mac):
Click a player’s nickname (in the lobby) , then click the 🚫 icon at the bottom of the window.
On smartphone/tablet:
Tap the player, then tap the circle with the diagonal line in the centre.
Screenshot:
https://tinyurl.com/2y3752eb
If you cleared your cache or deleted your cookies, then your settings were lost.
That includes the list of players you had blocked. You will need to set them again.
Important:
Games against guests are always unrated. You cannot win or lose rating points when playing them.
Kind regards