Bug of redstone auto update

some time ago, i trying solve a bug of redstone, a new block, the observer, did not show so many problems, except that it self-updates when we enter in world(type, a redstone is on and connected the a observe, he self-update and send a load, same though the redstone has not changed, has not off), but, the redstone, herself, does not update itself, i am referring the hour that we entered in world, in the following situation, we see this bug, a redstone(is on with lever or redstone torch) is connected with a dispenser(with water bucket inside) and you go out and then, you enter in world again, and you realize the bug, in almost all components of redstone, i saw some type bug, that it seem with this, i speak in almost all why the piston also showed this same problem, but the piston, when we enter in world, the piston is off, only after a time(almost no time), he is on, then, please solve this bug. My phone is galaxy j2, but i see this problem in other phone, like galaxy j5