I have had the same issue and for me it was to start with something more gripping.

I had a long list of really technical and hard to read books. So faced with reading them, I always defaulted to something easier.

Instead, if you start with something gripping and easier to read (even some trashy fiction) it builds up momentum and the habit. Once you get some momentum you can start tackling the harder books, alternating back to easier stuff when motivation wanes