I have a similar situation with you @toytu.When my daughter's visa delivered there was no decision letter inserted. So, I let her went to VFS to ask the "decision letter for Entry clearance" which is very important to show in UK border and collection of BRP and the staff said that we don't need anymore as it was saying in the sticker already. We arrived in the UK on the 24 of November with no hassled at all but my concern now is the BRP, where and how to collect as we have no letter to show. Anyone can help me, please?
They asked me the decision letter then the post office staff tried to checked also but totally no bro for my daughter. It cause a problem for me now.