Small muscles, small jumps
Unlike the squat that has huge leg muscles to grow, the press relies on delts and triceps, which are small, so linear weight jumps stall fast. Switch to fractional plates and add 0.5 to 1 kg at a time.
The overhead press uses small delt and triceps muscles over a long range, so it moves in tiny jumps, not big ones.
The overhead press is driven by relatively small shoulder and triceps muscles moving through a long range, so it naturally progresses slower than the bench or squat. Jumping the standard 2.5 kg per week is too much; use microloading of 0.5 to 1 kg. Add triceps and delt volume, double progression on reps, and make sure you are not just short on recovery or protein.
Unlike the squat that has huge leg muscles to grow, the press relies on delts and triceps, which are small, so linear weight jumps stall fast. Switch to fractional plates and add 0.5 to 1 kg at a time.
Pick a range like 5 to 8 reps, add reps at the same weight until you hit the top of the range on all sets, then bump the load and drop back down. This lets you progress when you cannot add weight weekly.
Weak triceps and side and front delts cap your press. Add overhead triceps extensions, lateral raises and some incline pressing so the supporting muscles grow. Bracing your glutes and abs also stops power leaking through your torso.
The overhead press uses small delt and triceps muscles over a long range, so it moves in tiny jumps, not big ones.