Having the same problem as a number of others, just started happening last few playing sessions. The game runs fine for a while, then mid-match will suddenly grind to a halt. No crashing to desktop just lists 18.2.2f1055984 (staging) on windows task manager.
No changes to any of my settings before this started happening, reducing graphics etc. removing custom graphics etc. makes no difference. I use Avast free antivirus, and Malwarebytes - no changes to these either recently, and having them off makes no difference.
Dxdiag attached below.