I think pretty much all insurance companies raise rates on a regular basis. In the past I used to stay with one company for many years, but no more. It doesn't pay to do so. I was with Allstate for many years until their rates got ridiculously high so I started shopping around. Ended up saving about 40% if I remember correctly. I was with the new company for about 10 years and they, of course, did the same thing. Earlier this year I switched again.
This time I contacted a broker who did the shopping for me. Saved me a bundle. My annual premium went from $900 (with Liberty Mutual) to $394 (with Progressive) for the exact same coverage. And before my bi-annual premium was due with Progressive I got an e-mail from the broker saying they automatically evaluated my options and suggested I stay with Progressive for now. I like that.
Progressive's rate, however, has gone up $8 per year after just six months though.
I'd suggest you contact these folks and see what they can do for you. There's no cost to you - I assume they get a commission from the insurance company you end up going with:
https://www.answerfinancial.com/