Yamaha CP33 Sustain pedal producing percussion sounds when actuated

Using Pianoteq 8 Stage, the MIDI log reports just Channel 2 Controller 64 values incoming.
Reading old posts on similar issues, the MIDI interface and cable were mentioned as possible causes.
I changed from the MIDI input on my Focusrite 4i4 to an input on my Cakewalk UM-3G which made no difference. The cable is by Stageline and I have not changed it.
The older posts have notes being recorded in the MIDI log which I am not experiencing.
Different percussion sounds happen for different Pianoteq instruments, sometimes combined bass drum and sizzle cymbal. These sounds are visible on the Pianoteq output meter at about a third the bar width of the piano sound itself.
I'd be most grateful if anyone has experience of this and can share any information.