BLE: Too many registrations for 'notify' or 'indicate'

Hi all,
My ESP32 is connecting to several BLE servers. During service discovering and registration of ‘notify’ or ‘indicate’, I get the following error message:
“BT_APPL: Max Notification Reached, registration failed”

Has somebody ever seen such a limitation and perhaps knows, how to change it?
I need to connect 4 BLE servers, each with 2 ‘notify’ and 1 'indicate, which results in a total of 12 registrations.

Thanks for any inputs!

Kind regards
Rolf