Notification to Update to 5.0.1 is gone on Nexus 7 2013 topic

HI,

I got a notification few days ago that 5.0.1 is now available for my Nexus 7 but when I finally decided to upgrade, the notification was gone and checking system updates show that my system is up-to-date. Anyone know how I can get it back? I don't want to use the zip file and sideloading. My device is a bit complicated because I have Multirom and Ubunut Touch.

Thanks.