No boot when pulsing signal on GPIO3

[ELAN4566]

Hi,

My ESP32-WROOM-32 is on a custom board. The firmware was loaded, everything OK. In my design I use most (all) GPIO ports including GPIO3 as normal IO port, not as UART RXD. At boot time, there is a pulsing signal from a peripheral on GPIO3. In this situation, the ESP32 does no longer starts. If I set logical H or L to the GPIO3, then the ESP32 boots normally.
If I use a port other than GPIO3, the ESP32 boots normally. But this is not a solution because I have to use all of the 22 GPIO as outputs.

Is this situation known and can I do something about it? E.g. eFuses ?

Regards,
Erich