Changing modes when selecting a track that contains a specific device

hello.
sorry for my bad english

im trying to write a script that does change modes when i select a track that contains a specific device regardless of its position.

what i want to achive is:

lets say i have 3 tracks:
track 1 contains an arpeggiator, Serum, an fx device or someting else
track 2 contains serum and another device
track 3 contains a max device and kontakt

if i click track 3 i want my script to change to "kontakt mode" so that i can control parameter 1-8 from the max device. ( this works flawless so far)

if i click track 1 or 2 i want the script to change it to "synth mode" so i can control parameter 1-8 from from Serum regardless of its position. this is where problem starts.

the script does change to synth mode and i can also control the parameters from serum regardless of its position. but to get my knobs led updated i always need to select an empty track first and go back to the track that i want to control

any hint what im doing wrong here?