new Core2 user - unable to run UIFlow

puzznic

hello,
I just received my new Core2 and, after following the excellent UIFlow Quick Start I was able to successfully install the Win10 driver, and run the M5Burner.
however, while burning the UIFlow_Core2 v1.7.1-core2 (or any other previous version actually) successfully completes, after the device resets I only see an on but empty screen - no UIFlow logo or the expected mainpage is displayed.

this is especially puzzling to me as I can successfully burn and run other apps, such as the downloadable Core2FactoryTest or draw_by_touch for example, without any issue.
am I missing something here ?
thanks a grand for your help.

=================
Start Burn
=================
--chip esp32 --port COM5 --baud 1500000 --before default_reset write_flash -z --flash_mode dio --flash_freq 80m --flash_size detect 0x7ff000 C:\Users\vpennel\Downloads\M5Burner\packages\fw\other\wifi.bin 0x1000 C:\Users\vpennel\Downloads\M5Burner\packages\fw\core\UIFlow_Core2-v1.7.1-core2.bin
=================
esptool.py v2.5.0
Serial port COM5
Connecting...
Chip is ESP32D0WDQ6 (revision 1)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse
MAC: b8:f0:09:c5:b1:34
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 1500000
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Compressed 100 bytes to 24...
Writing at 0x007ff000... (100 %)
Wrote 100 bytes (24 compressed) at 0x007ff000 in 0.0 seconds (effective 267.3 kbit/s)...
Hash of data verified.
Compressed 8376320 bytes to 3457107...
Writing at 0x00001000... (0 %)
[...]
Writing at 0x0034d000... (100 %)
Wrote 8376320 bytes (3457107 compressed) at 0x00001000 in 55.2 seconds (effective 1213.3 kbit/s)...
Hash of data verified.
Leaving...
Hard resetting via RTS pin...
=================
Burn Successfully
=================