FabFilter

After I send MIDI messages for banks and program changes for 10/20 times, Timeless 2 Program Change automation stop working, and keep frozen on the same preset, forever.

Try it with FL studio and MIDI Out plugin.

I guess it is a bug, isn't it? I don't have trouble with other plugins.

I just tested this with FL Studio 11 and Timeless 2.23, VST 2 version 32-bit. I could change presets hundreds of times without any problem. So unfortunately I couldn't reproduce your issue. Are you using the same version and plugin format?

Cheers,

Try with two instances of Timeless 2, set to two different MIDI Ports.