Need advice from running shoe experts Re: Saucony shoes

This past year I’ve done almost all my running in Saucony Type A3/A4 shoes. Not super high volume, but I’ve done quite a bit of running on them; over the year my volume has varied from 20-45 miles a week. During that time I’ve never had any type of aches or pains.

I’m starting to get ready to build for IMTX and wanted to transition to a shoe slightly more built for training and higher mileage, and of course, the Kinvara seemed like the perfect solution! I ordered a pair that arrived at the end of last week and have only done about 15 miles in them. They felt great during the runs, but now my knees are killing me! I had to take yesterday off from running because they hurt. I’ve also had tight calves which I don’t usually get from my running.

My understanding was that the Kinvara is a neutral shoe just like the Type A4 but with more padding. Is there something I’m missing here? Have I somehow completely misjudged my running gait/style? For now I’m going back to flats until I can figure out.

Thanks for the help!