Visual settings change on their own

Every time I play this game I get unbearable lag spikes which are solved by putting every thing on low/off and putting render scale on 75%. The problem comes when I quit OW and the setting change whenever i reload the game. I keep getting spikes and I go back to setting and I see render scale back to 100% and all of the visual stuff back on High. I don’t like this as every time I load the game up I have to change these settings again. It is really annoying