LPC55S69 flash freezes

The freeze occurs very often. Flash never continues when at this state.
Version in use: ddf36148a959fe27598c6d244b1039cd7b888293

$ pyocd flash -vvv -u 023600001985ea0a00000000000000000000000097969905 ~/mbed_cliapp_LPC55S69.hex 
0000286:DEBUG:session:Project directory: /home/raas/pyOCD
0000288:INFO:board:Target type is lpc55s69
0000297:DEBUG:dap_access_cmsis_dap:CMSIS-DAP probe 023600001985ea0a00000000000000000000000097969905 firmware version: 1.10
0000305:DEBUG:sequencer:Running task load_svd
0000305:DEBUG:sequencer:Running task create_flash
0000306:DEBUG:sequencer:Running task dp_init
0000344:INFO:dap:DP IDR = 0x6ba02477 (v2 rev6)
0000344:DEBUG:sequencer:Running task power_up
0000346:DEBUG:sequencer:Running task find_aps
0000359:DEBUG:sequencer:Running task create_aps
0000360:DEBUG:sequencer:Running task create_ap.0
0000365:INFO:ap:AP#0 IDR = 0x84770001 (AHB-AP var0 rev8)
0000369:DEBUG:ap:AP#0 default HPROT=3 HNONSEC=1
0000371:DEBUG:ap:AP#0 implemented HPROT=f HNONSEC=1
0000380:DEBUG:sequencer:Running task create_ap.1
0000384:INFO:ap:AP#1 IDR = 0x84770001 (AHB-AP var0 rev8)
0000386:DEBUG:ap:AP#1 default HPROT=3 HNONSEC=1
0000388:DEBUG:ap:AP#1 implemented HPROT=f HNONSEC=1
0000393:DEBUG:sequencer:Running task create_ap.2
0000399:INFO:ap:AP#2 IDR = 0x002a0000 (proprietary)
0000399:DEBUG:sequencer:Running task init_ap_roms
0000399:DEBUG:sequencer:Running task init_ap.0
0000432:INFO:rom_table:AP#0 ROM table #0 @ 0xe00fe000 (designer=015 part=000)
0000440:INFO:rom_table:[0]<e00ff000:ROM class=1 designer=43b part=4c9>
0000440:INFO:rom_table:  AP#0 ROM table #1 @ 0xe00ff000 (designer=43b part=4c9)
0000450:INFO:rom_table:  [0]<e000e000:SCS-M33 class=9 designer=43b part=d21 devtype=00 archid=2a04 devid=0:0:0>
0000481:INFO:rom_table:  [1]<e0001000:DWT class=9 designer=43b part=d21 devtype=00 archid=1a02 devid=0:0:0>
0000508:INFO:rom_table:  [2]<e0002000:BPU class=9 designer=43b part=d21 devtype=00 archid=1a03 devid=0:0:0>
0000562:INFO:rom_table:  [3]<e0000000:ITM class=9 designer=43b part=d21 devtype=43 archid=1a01 devid=0:0:0>
0000600:INFO:rom_table:[1]<e0040000:TPIU-M33 class=9 designer=43b part=d21 devtype=11 archid=0000 devid=0:0:ca0>
0000605:DEBUG:sequencer:Running task set_ap1_nonsec
0000610:DEBUG:sequencer:Running task init_ap.1
0000630:INFO:rom_table:AP#1 ROM table #0 @ 0xe00fe000 (designer=015 part=000)
0000637:INFO:rom_table:[0]<e00ff000:ROM class=1 designer=43b part=4c9>
0000637:INFO:rom_table:  AP#1 ROM table #1 @ 0xe00ff000 (designer=43b part=4c9)
0000644:INFO:rom_table:  [0]<e000e000:SCS-M33 class=9 designer=43b part=d21 devtype=00 archid=2a04 devid=0:0:0>
0000649:INFO:rom_table:  [1]<e0001000:DWT class=9 designer=43b part=d21 devtype=00 archid=1a02 devid=0:0:0>
0000654:INFO:rom_table:  [2]<e0002000:BPU class=9 designer=43b part=d21 devtype=00 archid=1a03 devid=0:0:0>
0000659:INFO:rom_table:  [3]<e0000000:ITM class=9 designer=43b part=d21 devtype=43 archid=1a01 devid=0:0:0>
0000664:INFO:rom_table:[1]<e0040000:TPIU-M33 class=9 designer=43b part=d21 devtype=11 archid=0000 devid=0:0:ca0>
0000664:DEBUG:sequencer:Running task create_cores
0000670:INFO:cortex_m_v8m:CPU core #0 is Cortex-M33 r0p3 (security ext present)
0000678:INFO:cortex_m:FPU present: FPv5-SP
0000685:INFO:cortex_m_v8m:CPU core #1 is Cortex-M33 r0p3
0000690:DEBUG:sequencer:Running task enable_traceclk
0000694:DEBUG:sequencer:Running task create_components
0000694:DEBUG:coresight_target:Creating DWT component
0000698:INFO:dwt:4 hardware watchpoints
0000699:DEBUG:coresight_target:Creating BPU component
0000701:INFO:fpb:8 hardware breakpoints, 1 literal comparators
0000701:DEBUG:fpb:fpb has been disabled
0000702:DEBUG:coresight_target:Creating ITM component
0000707:DEBUG:coresight_target:Creating TPIU-M33 component
0000709:DEBUG:coresight_target:Creating DWT component
0000713:INFO:dwt:4 hardware watchpoints
0000713:DEBUG:coresight_target:Creating BPU component
0000715:INFO:fpb:8 hardware breakpoints, 1 literal comparators
0000715:DEBUG:fpb:fpb has been disabled
0000716:DEBUG:coresight_target:Creating ITM component
0000721:DEBUG:coresight_target:Creating TPIU-M33 component
0000723:DEBUG:sequencer:Running task check_for_cores
0000723:DEBUG:sequencer:Running task notify
0001111:DEBUG:flash_builder:Analyze time: 0.000981
0001111:DEBUG:flash_builder:Using double buffer sector erase program
[                    ]   0%0001209:DEBUG:manager:added=[] removed=[]
0001209:DEBUG:manager:bps after flush={}
0001209:DEBUG:manager:added=[] removed=[]
0001209:DEBUG:manager:bps after flush={}

Start by reproducing the pyocd flash -vvv command against the LPC55S69 and inspect where the verbose sequence stops after double-buffer sector erase programming begins. Done means flashing the provided HEX completes reliably instead of freezing at 0%.