Is cumbersome used correctly in this sentence?

No, I would not use cumbersome here. Awkward would be a better word. Cumbersome is usually used to describe something large and unwieldy - like a cumbersome parcel, or " I found the diving suit rather cumbersome to wear".

The dictionary definition in current use is:
Inconvenient in size, weight, or shape; unwieldy, clumsy to handle.

The secondary definition: "Involving effort but serving no purpose; needlessly complicated or indirect." only applies if the word is being used figuratively, e.g. government had become so enormous, so cumbersome, so ridden with bureaucracy.

No,cumbersome refers to a heavy or awkward load or burden.I would use tiresome/inconvenient etc instead.

yes

Cumbersome is correct.