PBO limits based on power and temperature so it should be of no issue , you just won't boost as high as a decent aftermarket cooler. Your board will likely limit you somewhat under heavy sustained load, but for something like gaming there ought to be no issue.
Could be thermal throttling so check your temps also check your power plan in windows, should be on balanced
should i be using ryzen balanced or regular balanced with and without PBO. i messed with it although tests seemed slighty better with ryzen balanced over windows balanced? temps also never really went over 70c