Ok. Here's the situation:
I have global IPv6 addresses assigned to a number of interfaces. At one point, I went through and disabled all of them at once. When I re-enabled them all at once, they turned red and went invalid! This can be fixed by deleting the "invalid" address and re-assigning the address. I have a supout capture if mikrotik is interested.

yes please send supout to them, i have seen this as well.

I'm getting similar behavior. I just upgraded from 6.1 to 6.27
Prior to the upgrade, everything was working perfectly.

Here's the information I've collected:

- DHCPv6 still correctly receives the /64 from Comcast
- DHCP creates the dynamic pool "Comcast"
- IPv6 Address ::1/64 configured "from-pool=Comcast" in Winbox on interface LAN
- IPv6 Address updates to show the prefix from Comcast e.g.: 2001:db8:1000:1000::1/64
- IPv6 Address never loses the 'I' invalid flag, and stays red in Winbox. It also never appears as a prefix in ND.

- I AM ABLE to ping the IPv6 address from elsewhere on the Internet, so the address is actually working, but because it is staying flagged as invalid, RA never begins advertising the prefix to my LAN devices.

If I hard-wire the exact same prefix::1/64 without the from-pool option, the Invalid flag goes away, and ND adds the prefix correctly.

Setting logging to debug has not shown anything exciting. The last event to appear is:
dhcp, debug "bound to 2001:db8:1000:1000::/64"
No errors or complaints about the prefix or the pool or anything else.

Same problem here. Any info? Btw, address is not marked as "invalid" in winbox (only G flag appears), but "IG" is seen in cli interface.

This Problem is still present in ROS 6.29.1. Mikrotik, please do something about it!

Fixed in 6.30rc24, check please.