It's not abnormal for games to have issues with Anti-Virus software. My recommendation is to add the game to the exclusions in Emsisoft Anti-Malware. You can either add the main Black Ops 4 executable itself to both the scanning or monitoring exclusions, or the folder Black Ops 4 is installed in.
If Black Ops 4 is in your SteamApps folder, then you can add that folder to the exclusions as well. Just be sure you trust any games that are running out of that folder before you add it to the exclusions.
Here's a link to information on adding exclusions in our products: https://help.emsisoft.com/en/1815/how-do-i-exclude-a-program-from-an-emsisoft-product/