Avast App interfered with firmware update?

I installed Avast Mobile Security on a new Samsung Galaxy J5 (2016) and then installed a software version and firmware update that the phone offered. After the update installed I noticed a slowing/decrease in performance (not major, but definitely not as good as before).
Is it possible that the Avast App interfered with the firmware update and caused this to happen?
(If yes, I assume the only remedy would be to factory reset the phone and not have Avast installed when installing firmware updates in the future.)

I factory restored the device and weirdly enough the update stayed baked into the phone. The Security Patch level stayed as March 2017 instead of the original way it was when opening the device for the first time (September 2016). Apparently even factory restoring doesn’t remove system firmware updates in Android Marshmallow.

And you still experience slower device when you do clean install of Mobile Security?

I didn’t re-install it yet, but does factory restoring not remove android security patch updates?