IPV6 can not working with PPPoE dial in china ISP

Hi,

I have a problem with IPV6 and would like to ask for help, thank you in advance.

I am using R7000P + FW:1.3.3.142 - Hot Fix.
My ISP(ChinaUnicom) provides IPV6 service.
When I use optical network unit to dial, R7000P is only used as router(don't dial), and set IPv6 to pass-through in R7000P, my computer(windowns and mac) and my iphone can get the IPV6 address correctly, and pass the test-ipv6 test.
However, when I set the optical network unit to bridge mode, dial(PPPOE) in the R7000P and set the ipv6 to PPPOE mode, the R7000P prompts that it can obtain the IPV6 address of the WAN, but my computer(windowns and mac) and my iphone can not pass the test- ipv6 test, them have not a IPV6 address.

From what I understand, there are others who have the same problem as me.
I'm not sure if this is a problem with the ISP or the R7000P, can you give me some advice?

Thanks again.