Classic IT Band pain. At least that’s what it was for me. Even the downhill parts. Lookup some muscle rolling routines for IT Band pain.
Get one of these to keep going in the meantime. https://www.amazon.com/dp/B01IBU5WZS/ref=cm_sw_r_cp_api_glt_fabc_WMHJH4SC0373F2C5BRRD?_encoding=UTF8&psc=1
Unpopular response here on runnit, but the biggest key to my success has been wearing an IT band strap during runs. I got mine on amazon.
The biggest success I’ve had with it is using an IT band strap. Here’s the one I use: IT band strap
I only use it on runs longer than 2-3 miles but I’ve had zero pain since using it. I also recommend Yoga for Runners which you can find on amazon prime video for free if you have prime. I hate yoga but it really helps and you can just use the strap/belt stretching from the video after runs too.