observers freeze/stop working underwater

i have this really massive kelp farm that harvests kelp using a 2 way flying machine. when i used it today i found that the machine would stop half way(more or less) in the farm when i broke the sticky piston which wouldnt fire even after updating the observer to my surprise i found that the observer was frozen in the giving out a signal state with the hole on its back constantly lit red

this can be solved by directly powering the piston using a button/lever, but under water that is painstakingy difficult.

i have made sure that all the things are chunk aligned but this freezing happens just before or after passing through a chunk border