Issues with Deep Sleep

[appcoders]

Hello everybody.
I have a strange problem with deep sleep - not me but a ESP32-WROVER module
I have two Inkplate 6 devices. Both use the same type of LiPo Battery. On device A deep sleep works fine, after 15 minutes the device wakes up, gives me wake-up-reason 4 and refreshes the display. Device B just crashes/reboots when trying to enter deep sleep. Now, the funny part: Only happens when on battery (battery has >4V). As long as the device is connected to the computer, deep sleep also works on device B. I remove the USB cable and when devices awakes from last successfully entered deep-sleep, it just refreshes and reboots again and again. Also tried the battery from device A on device b - same behavior.
So where can I search?
Is the ESP-WROVER somehow defective?
Thanks in advance.

[aliarifat794]

Try to add a capacitor (e.g., 100 µF - 470 µF) across the battery terminals (between VCC and GND) to smooth out any voltage dips or noise when the ESP32 wakes up.

[appcoders]

Hi,
Thanks for your suggestion. If I understand you correctly you think the board takes too much current on waking up?
Maybe I did not explain correctly in my first post - the issue is that the ESP32 does not enter deep sleep mode at all when running from battery.
Is there something that could prevent deep sleep when running from battery?
Thanks.