Multiple mavros node problem

Hi I’m working on multiple UAV with multiple tag ns mavros
And I have two problems
one is that TF old data problem

Warning: TF_OLD_DATA ignoring data from the past for frame base_link at time
1.4906e+09 according to authority unknown_publisher Possible reasons are listed at tf/Errors explained - ROS Wiki

This is the warning msg and I could’t find out the reason

And second problem is

node [uav1/mavros] publishing transform [base_link] with parent [map] already published by node [uav2/mavros]

This is the error msg which I can get through ‘roswtf’ command

As I found out mavros are overwriting tf conversion with same frame_id so I have to change frame_id in yaml file but I don’t know how(not sure this is the solution)
and there are too many frame_ids such as (map, base_link, fcu, local_origin, fcu_utm, set_point)
I don’t know the difference.
in REP_105 there are only map and base_link and no document with modifying yaml file

Any help for noob is appreciated