But then I tested the keyboard with an oscilloscope. It turns out some messages are not being sent from the keyboard itself.

So the keyboard is at fault here. I will either try to get it fixed or get a simple modern USB MIDI keyboard.

I have an 88 key Technics SX-PR110 (an old keyboard). I just bought a "Miditech Midilink Mini" driverless, class compliant USB to MIDI interface cable. I connected it to the Technics and my PC via one of the USB 2.0 ports.

In both Pianoteq (Trial) and another software (Reaper) when I record a short part from a song with the software from the Technics, there are notes missing and there seem to be notes that are stuck on. I have a high spec computer so that is not the issue. This is on Windows 10.

The notes missing are not the disabled keys for the Trial of Pianoteq, I can assure you.

I tested the cable connected to the keyboard with the "Pocket Midi" application. It seems to output keys fine. It outputs a 0x90 signal with the velocity for a given key, and instead of outputting 0x80 for key off, it outputs another 0x90 with ZERO velocity when I release a key.

It also outputs an FE signal regularly, about once every 300 ms, which I suppose is a timing signal.

I find it odd that two separate softwares both have this issue with MIDI. It seems the MIDI is not being interpreted correctly by the softwares.

I've tried all the Dialect options in Pianoteq. I'm using ASIO for output. Multicore rendering and CPU Overload detection are both ON (default). Maximum polyphony is set to 48. Everything is at default settings.

Any advice on how to get this working is appreciated!

It's the MIDI cable adaptor.
Don't buy such devices. Buy a solid appliance.

Two examples

e.g https://www.thomann.de/gb/steinberg_ur22_mk2.htm or https://www.thomann.de/gb/focusrite_sca...rd_gen.htm

In both Pianoteq (Trial) and another software (Reaper) when I record a short part from a song with the software from the Technics, there are notes missing and there seem to be notes that are stuck on. I have a high spec computer so that is not the issue. This is on Windows 10.

The notes missing are not the disabled keys for the Trial of Pianoteq, I can assure you.

I tested the cable connected to the keyboard with the "Pocket Midi" application. It seems to output keys fine. It outputs a 0x90 signal with the velocity for a given key, and instead of outputting 0x80 for key off, it outputs another 0x90 with ZERO velocity when I release a key.

It also outputs an FE signal regularly, about once every 300 ms, which I suppose is a timing signal.

I find it odd that two separate softwares both have this issue with MIDI. It seems the MIDI is not being interpreted correctly by the softwares.

I've tried all the Dialect options in Pianoteq. I'm using ASIO for output. Multicore rendering and CPU Overload detection are both ON (default). Maximum polyphony is set to 48. Everything is at default settings.

Any advice on how to get this working is appreciated!