I replaced my router because my old one (Billion 8800 NL R2) kept crashing around 4am UTC every couple of months. Sometimes it didn't crash but instead just dropped IPv6. My new router - A Billion 8800AXL R2 - is doing the same thing. It hasn't crashed yet but after being in use for barely 13 hours it dropped IPv6. I've raised the issue with Support and with the Billion people but has anyone else had their router dropping IPv6 sessions?
The good news is that the replacement router has never dropped IPv6 since installing it. Looks like an issue with the older router.