OAI UE in SA FDD test, PRACH RA-RNTI mismatch with 3rd-party gNB when msg1-FDM is 4

Hi,

I'm using latest develop branch with USRP B200-mini as nrUE, when testing SA FDD with 3rd-party gNB and gNB configure msg1-FDM = 4 in SIB1 message, it seems UE will randomly choose PRACH frequency resource ID.

When this PRACH frequency resource ID is not 0 (from UE log as below):

[MAC]   f_id 2 t_id 4 s_id 4 ul_carrier_id 0 Computed RA_RNTI is 0x08FD
[NR_MAC]   PRACH scheduler: Selected RO Frame 605, Slot 4, Symbol 4, Fdm 2
[PHY]   PRACH [UE 0] in frame.slot 605.4, placing PRACH in position 2828, Msg1/MsgA-Preamble frequency start 0 (k1 0), preamble_offset 0, first_nonzero_root_idx 0, preambleIndex = 1
[MAC]   [UE 0] RAR reception failed

But from gNB log and IQ capture, UE is sending PRACH at this slot (605/4) with frequency resource id = 0, so gNB calculated RA-RNTI is 61, which doesn't match with UE, then RAR reception failed.

Below is complete UE log:

prach_short_sequence.log

Could someone please help check this issue? Thanks.