Yeah F should be 25.mm, are you using something other than PLA, Shrinkage? Check you extrusion rate by doing the 100mm test, you might just be over extruding. Luckily the parts should flex and still work.
Even the 23.5mm parts are not made at 23.5, all my parts have a little extra or a little less but in depending on print orientation. the locks all should be designed at 25.2mm and print at 25. sounds like you print or filament is causing some issues.