RTN support configuring manual sharing Lag with two 1+1 members, only the main interface of 1+1 protection can be configured into Lag. And don't support configuring 1+1 with two Lag.
you can descripe your detail configuration, then I can answer you the reason.
for example:
1. what is your current version?
2. which boards does the Lag contains currently?
3. which boards do you want to configure 1+1?