Reversal in arbitrage rates at BX

Over the past few months, I have noticed that the BTC prices at bx.in.th have consisently been about 1.5% - 2.5% below the international exchanges. I find this peculiar because in previous times rates would usually be 3% - 5% above the international exchanges.

I am trying to understand what this implies with regard to Thai investors interest in the space. My initial thought is that this means Thais have largely stopped buying, and thus the rates need to drop below the international rates in order for it to make sense to buy on bx and sell overseas.  That would imply that previously Thais were net purchasers of the currency, and the rates had to be above the international exchange to justify buying overseas and selling to Thais.

Have I understood the dynamic correctly, or are there other factors that I am not considering which would account for this turnaround?

Did the new tax laws implemented by Thai authorities have a chilling effect on interest in Bitcoin in Thailand?