Personally I would never auto renew anything - doing so would reduce the likelihood of getting a discount rather than pay full price on auto renewal.
This is true for almost any program/software renewal, handle it yourself and you are likely to be offered a reduced price as the due date gets closer.
Note I’m using Avast Free and I probably get less hassle than a paid user, in my opinion this is counter productive. Not using Avast Premium Security, I don’t know if there is anything in the settings about notifications (relating to renewal) not being displayed e.g. Settings > General > Notifications - Silent Mode ?
