See a few comments here, regarding USB-A vs. -C when powering a dock and L5 together: [MyL5] Received my Librem 5 (Evergreen)
Related info: New Post: My First Week of Librem 5 Convergence and https://source.puri.sm/Librem5/community-wiki/-/wikis/Frequently-Asked-Questions#21-how-long-will-be-the-battery-life-of-the-librem-5-evergreen