De tuning problems and action related question

[Awkwardturtle!]

So I got my squier P/J setup like about a week or two ago fitted with new strings, intonation, truss rod adjustment, and action.

I detune a lot like to drop D and C but whenever I detune my other strings detune with it after me playing only just a little bit with it
like my A string would be a B flat and such

And about the action,
the action was really low which was how it was suppose to be (played like butter on E tuning) but when I played on C tuning it had severe fret buzz. so I brought up the action until it had very little fret buzz ( the action is really high now)

is this normal? If i detune a lot should I keep my action high? When I detune how come my other string become out of tune with it?

I'm so confused!

[Burlington]

Changing the tuning will cause the neck to bow differently, making other string go out of tune and changing the action. If possible, a bass should be set up with a specific tuning in mind. Larger gauge strings also help with lower tunings.

Good luck!

[Awkwardturtle!]

Yea I know I told him that i frequently drop tune but a larger string gauge will help for sure thanks