Up until yesterday, my framework laptop honored the 50% charge limit I had set in BIOS. Mysteriously it stopped doing so yesterday and charged to 100%. It keeps doing that.
I double-checked BIOS settings and everything is intact, set to 50%.
If you have 11th gen and BIOS 3.10 allow the laptop to drop below 50%. In an earlier BIOS, 3.07, once the voltage rises above the threshold it is not a limiting parameter any more.
The actual voltage when you were using it before switching off may have been set by the 50% but then after switching off the voltage may rise a little, maybe only 0.1V but that may put it beyond the value set for 50%.