First thing I noted when I purchased my vehicle in March 2020, was a tappety/knocking* sound at around 1500 - 2000rpm. Only really noticeable when accelerating around town or when going from a 30 into a 40/50.
Took it back to dealership who stated they replaced the transmission mount(s).
I've either just got used to it or it really did cure it, but I don't notice it now.
Vehicle is a 1.5 iVTEC, 6 Speed manual.
HT* one person's 'tappety', is another person's 'knocking'!