Been fairly consistent for a while now, and as I understand it there's no client side fix.
I've confirmed that it's not just me affected. Is there anything that can be done to fix it?

It's a Valve issue. A few third party fixes have been made, which work for a while and then break when there is an update.

I have applied a new fix and they should no longer appear, until the next time.

Thanks for reporting.

there back