The topology can be referred to the attachment. There are two physical links between CE1 and PE1. The upper link belongs to VPNA and the lower link belongs to VPNB. CE2 also belongs to VPNB. PE1 from other PE through RR sends the route of VPNA to VPNA of CE1 through EBGP and upper link of CE1--PE1. CE1 sends the route and local route to VPNB of PE1 through EBGP and lower link of CE1--PE1. When EBGP is established between CE1 and PE1, PE1 configures permit order of as-path to circulate once. Before the network is normal and PE and RR act as C device. But when it changes as Huawei device, VPNB of PE2 does not receive the route of PE1 even if we use the same configuration.
Add permit AS No of AS-path to circulate once on RR and PE2 of Huawei device and the problem is solved.
The configuration is not problematic. Check BGP neighbor and it is correctly established. BGP route attribute is problematic.
Check the route of VPNB on PE1. CE1 has informs the route of VPNA learnt from other places and local route of CE1 to VPNB. Use the command dis bgp vpnv4 all routing-table peer RR adv-routes on PE1 and it is confirmed that PE1 has informed the route of VPNB. Use the command dis bgp vpnv4 all routing-table peer PE1 received-routes on RR and there is no route of VPNB. It is certain that RR discards the route informed by PE1. PE1 informs VPNB route to RR and its AS-path contains the same AS No as RR. C device reserves AS No of the route from IBGP and does not compare it. But VRP3 of Huawei device compares AS No of the route from IBGP. If it is the same, the route will be discarded.
Use display command and necessary debug command as much as possible.