NR UE hanging after `RA-Msg3 transmitted` log

Scenario:

sudo taskset -c 4,5 ./nr-softmodem -O ../../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band1.u0.52PRB.usrpb210.conf --gNBs.[0].min_rxtxtime 6 --rfsim

sudo taskset -c 5,6 ./nr-uesoftmodem -r 52 --numerology 0 --band 1 -C 2115650000 --CO -190000000 --uicc0.imsi 001010000000001 --rfsim --ssb 192

The taskset command is due to the issue being intermittent on slower CPUs. Assigning 4+ CPUs seems to resolve this issue on my PC

Observation

NR UE hangs with these statements printed at the end:

[NR_MAC]   [UE 0][RAPROC][429.2] Found RAR with the intended RAPID 2
[PHY]   RAR-Msg2 decoded
[NR_MAC]   [RAPROC][430.0] RA-Msg3 transmitted
Entering ITTI signals handler
TYPE <CTRL-C> TO TERMINATE

I have verified that the UE/gNB are still exchanging samples if rfsimulator using tcpdump -i any port 4043 so it is not hanging. The UE's UL_Actor is running so I think this is an issue with the UE state machine not changing the state correctly.