Well silent gaming mode is off by default.

I don’t know if it would be included in bugs to be resolved or I would expect to see lots more topics relating to this. Whilst it isn’t unusual to see the red x for a few seconds shortly after the avast icon appears, it should clear quite quickly.

If it does happen again on a regular basis - Try a repair of avast. Add Remove programs, select ‘avast! Anti-Virus,’ click the Change/Remove button and scroll down to Repair, click next and follow. You may need to reboot after the repair.