Update: Apple released the iOS 11.2.5 Update today, I recommend it for all Apple Pay Suica users.
The latest iOS 11.2.1 update did not fix the Suica notification bug for me. I installed iOS 11.2.5 developer beta 1 and am happy to report that Suica notifications are working again in that beta. 11.2.5 will be mostly performance tweaks, Apple Pay Suica performance seems to be getting attention in this round.
As a rule I do not install beta software on my iPhone but the 11.2 Suica notification bug was irritating, iPhone X Suica performance ragged enough and the iOS 11.2.5 update number jump low enough to give it a go.
I do not suggest that others do the same. Let me deal with the messy Apple Pay Suica testing and keep you up to date on beta progress in this blog.