Is the "timing issue" something like this? (As I am starting to be completely out of the loop what is being complained..)
About Cubase for example (its slightly old, things tend to change to better over time, but..yeah
"For instance, if you play regular 16th notes at 120bpm, each note will occur at an interval of 125ms, but when a soft synth is played 'live' through an audio interface with a buffer size of 5ms you'll perhaps hear them with spacings such as 125ms, 125ms, 125ms, 130ms, 120ms, 130ms, 125ms and so on, where occasional notes get shoved into adjacent buffers. For most people this is still scarcely audible, but if you raise the buffer size to 20ms then you might hear a string of 'live' notes emerging with spacings of 120ms, 120ms, 120ms, 140ms, 120ms, 120ms, 140ms and so on: the 'granularity' has increased."
"Most sequencers choose not to calculate any offsets within the next buffer relating to 'live' MIDI data — they just quantise them all to the nearest buffer boundary, and rely on the buffers being short enough to mask unwanted rhythmic artifacts. The main reason they do this is to keep every note's MIDI latency as low as possible, but at the expense of extra jitter." - Martin Walker SOS
Worst (in my opinion and many others anyway..) case would be Ableton Live. Theres even a special mention about it in the Virus OS release notes. "• Ableton Live still changes MIDI timing of tracks recorded with Virus Control instantiated"
Heres the link, if someone wants to read on.. https://www.soundonsound.com/t…ving-midi-timing-problems
Simple googlyeyeing "midi timing problems" will give you more insight which SW/HW have these problems and how possibly fix them
Edit: more about jitter in synths https://www.innerclocksystems.com/litmus
Hope this will give you the tools to sort out your "timing issues"