as said above. the major issue i have come across regarding silk touch pickaxes and deployers is that when put on a moving contraption(such as a minecart contraption or a gantry carriage contraption) and used for their intended purpose(that is, to break blocks), the pickaxes simply disappear of the contraption while it is in motion and the deployers do nothing. sometimes when the contraption is stopped the disappearance of pickaxes this way persists, permanently destroying the pickaxes.

This issue has been marked as stale because it has been inactive for 3 weeks. It will be closed if it remains inactive for another 3 weeks.

This issue has been closed since it has been inactive for 3 weeks since it was marked as stale.

Just sharing that for me the key was to put the deployer into Attack (not Use mode). I know OP states that they were in Attack mode already, so maybe they have a different issue, but for me it worked.

Are the deployers in punch mode? (Change with wrench)

when i said "set to break", i meant "in punch mode", so yeah

i'll check, give me a minute

alright, enchanted swords stay on, but dont affect creatures right in front of them. i should have expected that(becuase deployers affet things 2 blocks ahead), but that has little to do with the pickaxe issue

Do you have claims in that area? Like with ftb chunks, minecolonies?

i tried to recreate the issue again in a creative world, but its working there, so i am even more confused

i have no claims at all

Odd, so it works in singleplayer?

all attempts were in singleplayer, even the ones that did not work

also, i had an idea. maybe the silk touch enchantment on the pickaxes causes too much data to be stored on the contraption entity, causing the contraption entity to "shrug off" extra data?

Do other items disapper when putten into the deployer?

There is a strange issue with chunk borders and deployers that causes the deployers to get cleared (explained much better at 44:00 in this video , if the contraption starts in the same chunk as a Mechanical Saw.
Does the behaviour change if the deployers break blocks inside/outside their starting chunk?
(show chunk borders by pressing f3+g)

that is almost certainly the problem, i will see if the areas i tested crossed those borders.

answer: yes they do, and the chunk border is about the area i had problems, so i think that idea is correct