same problem here as well :(
same here. Mine has a oreo 8.0 feb 2018 patch and says that no new update available.
I have a solution to get 8.1 and the security patch update. Please follow below steps.
3)then force restart the device by pressing volume up key and power key button for 20 sec then device will vibrate 3 times and will restart. Let it start and when connected to internet,it'll show you 8.1 update.
Above steps were provided to me for enabling volte but instead they were successful in showing the 8.1 update in my case. Try it out.