Bug: Nexus Siege Horde Event Error (PC) no progress

Nexus Siege Horde Event Error at end of match no progress made to medals: Nexus Siege on PC .
Note: I notices intense lag on wave 1 as low as 15fps on a gtx 1070, i7-4790k, 8gb ram (Driver 465.89) the rest of the wave were 60-140fps or so, windows defender was off.