my personal experence with neons is they will just decide to go when they feel like it. they get so inbred these days. and my kulhi loach always does dashed after the light turns off. my Panda cories used to do a similar thing when i had them in a 90L but know in the 160L they don't.
Bumble bee gobies need a littlle salt from time to time don't they? try using some rock salt, we used to use it to fix all sorts of things in our tanks