Why Deliyannis bandpass filter with high Q does not have the expected transfer function bode plot
When plotting high-\$Q\$ transfer functions with any graphical viewer whether data are coming from a SPICE engine or a mathematical solver, it is important to maintain an adequate number of points per decade. 100 is usually enough for 1st-order responses but as soon as \$Q\$ is way above 1, you can potentially miss the peak if granularity is not good enough. For this purpose, you can push the number of points per decade to 1000 or even more if necessary.