Happened to me too. I think the update was released 3rd April and while everyone else was getting it straight away, I didn't get it until several hours later. The A55 is quite new isn't it? Wonder if the devs need to address that. Please reach out to them. They may even be working on the update for your model as we speak.
You could be right as it appears that only S series devices have got the new version. I'll reach out to them and see what happens. Thanks for replying.