When using KNX in cores > 2.3.0, the ESPAsyncUDP Library was used instead of the WIFIUDP Library. As now ESPAsyncUDP is no longer mantained and also it does not work in last version of the Arduino STAGE Core, now for all cores KNX will use the WIFIUDP Library.
Updated esp-knx-ip library with a merged version that allows to select multicast library to use:
* WIFI UDP (for esp lib 2.3.0 and up)
* AsyncUDP (for esp lib 2.4.0 and up)
The selection can be done with a definition key in the file esp-knx-ip.h