What is the reason for the failure of pre-authorization of foreign hotels with VISA credit card of China Merchants Bank?

It should be that the dollar is not enough! I'm ICBC visa, and I made a reservation at the Hong Kong Hotel! RMB is enough, but the pre-authorization failed! Call ICBC and say this reservation is in foreign currency. My dollar overdraft limit was not enough, and I couldn't book it the next day, and then I succeeded! ! ! But it's a lie. I thought that if the dollar was not enough, I would directly deduct RMB or something, but the bank said that some places can be used and some places can't! ! I don't think I understand what they are saying. For reference only! !