I'm more unsatisfied, then bored. I think a lot of the problem in both cases boils down to social relationships.
For example, I could bike or swim in both places, but if I don't connect well with those around me, even if it's a solo activity, the activity can become slightly unsatisfying in a way. Maybe the activity the Op likes becomes boring in Thailand because nobody else is interested in it here, or it just feels off and strange. like being around overweight guys drinking all the time then feeling unmotivated working out later in an empty gym. Whereas, if he was on Venice Beach he would be pumped to work out.