Is iQuery sent to each other among GTMs and LTMs? full mesh?

hi, we have 3 data centers and there are two LTM and one GTM at each data center.  All GTM are configured in the same sync-group. And LTM are added to local GTM server list. For this setup, normally we shall see the iQuery are sent bidirectionally with full mesh, right? I saw one GTM A sent iQuery to GTM B, but no iquery from GTM B to GTM A, is it normal? please advise, thanks in advance!