I have already installed and activated the SPI device as described in the WIKI. Unfortunately, the HAT is not always recognized. Commands sent to the HAT are sometimes answered with 0xff. For example, if I run a process in a second terminal (the CPU is under load), 0xff is always sent back. If a response is sent back other than 0xff, there are always 4 bytes 0x00 before the actual response byte. When I start the same program on the Raspberry PI, all requests are answered correctly. Can anyone give me a tip? Does something changed somewhere?