How can I stop secure browser from starting at boot after disabling

I’ve used this browser a few times and thus far have had no complaints, but every time I disable the option to run it at startup, it eventually winds up re-enabling itself again. No matter how many times I’ve gone through this process, it still finds some way to re-enable the option again. This is becoming more of a nuisance than a feature. How can I stop this?

Follow instructions from Bob: https://forum.avast.com/index.php?topic=232707.msg1539290#msg1539290

I gave it some time because it takes a short time period for it to start again, but after clean install it’s still managing to reconfigure itself to start at boot.