Bike won’t idle when warm

I have developed an issue where my bike (2005 VZ800 FI) will initially start and run fine, but once warmed up it starts to splutter and die. If riding it seems to drop one cylinder and sometimes pick back up again in a surge under acceleration.

I have replaced the plugs, tested the coils (both around 3.5 ohms and 17.7kohms between primary and secondary), replaced air filter and adjusted idle speed, all to no avail.

I’m now at a loss and joined the group to see if this is a known issue?

Any help would be mint!

Andy S