usually BLR follow OPR. BNM change the OPR and not BLR. Once OPR changed, the bank will reflect it on BLR. whenever that happen, not all the bank will change their BLR instantly. they will take some times to make such adjustment.

whenever there is adjustment with BLR, not necessarily there is affect on MOnthly Installment. If the bank increase the monthly installment, you can write in to the bank to stick back to Currently Installment. The only different is Tenure will increase. Based on my last loan, when the BLR change, it did not reflect my Monthly Installment. I still pay the same amount. but behind it, i already know my tenure will be longer. i'm not sure about the TnC now.

another case i experience is, under construction property, the bank will NOT state in the Monthly Installment. Instead, i received a letter from bank stating on the commencement date and amount for the installment.