I deal with insurance but not on the casualty side. (I can share my experience with you but from a consumers’ point of view and not the insurers’.)
There are things that insurers check in your personal life / background that may not appear to have anything to do with your driving but show if you’re a responsible person or not. (For example they may give better rates to a teen that’s a good student and raise the rates if he/she doesn’t keep up the good grades.)
With that being said it may be worth giving them a call to see if they can shed some light. They may also be able to give you a more competitive rate or offer you a discount if you take a defensive driving course.
Our premiums started creeping up as well- I attributed it to the price of used vehicles shooting upwards. (They also look heavily at your ZIP code, is there an area in your ZIP code with a high rate of accidents?)
When we added a teen driver the premiums more than doubled. We called an agent and got a quote that (with our new teen driver) was less than we were paying with GEICO before we added the teen driver so we switched.
Hope this helps.