Hello,
it happened to me on 2 rb500, upgraded and lost almost all wireless access list entries.
Jan
Remember the upgrade from 2.8 to 2.9 and 2.9 to 3 is a very big upgrade. When going from 2.8 to 2.9 we also had many things that wouldn’t upgrade. It’s always a good idea to install new hardware and make sure everything is working fine in the lab. You could now either install the new router you configured on the highsite, or upgrade the highsite and restore a backup made from your later version LAB router to the highsite. I personally prefer to replace the hardware.
Did you upgrade to 2.9.51 before the upgrade?