Welcome to Connect, @smasneri. While you’re waiting for other members to reply I found on Drug.com that 1-10% of patients taking Eliquis experience arthralgia, back pain, pain in extremity, osteoarthritis, muscle spasms, musculoskeletal pain, myalgia and arthritis. https://www.drugs.com/sfx/eliquis-side-effects.html

I can’t image tolerating that kind of pain for 5 months either if you think it’s from the Eliquis, especially since there are alternatives. Here’s a list of other blood thinners, many have been on the market for years, such as Warfarin.
https://www.singlecare.com/blog/eliquis-alternatives/
I hope you’re able to make a switch to see if it helps. You mentioned seeing a hematologist, do you have a blood disease that increases your risk of blood clots?