In regards to the coils, the click/snap connection on these is not on the plug end themselves, but the plug connector boot/resistor to the coil towers. The plug end is simply a coil spring that rest on the plug from compression.
These are known troublesome boot/resistors and should be changed [ $8 ea.] Your car is HFM [my assumption-dist-less ign.]and when there is ignition failure, [ skip] , the ecu also shuts down fuel.
The other plug ends [ #1,3,and 5 hold up better as they are not trapped between the coil and plug chamber [ heat damage]
So, I would lift each coil and check that the boots all "POP' back on to the coils. [ better to change them at the same time]
The other click/snap connection is a screw shaft that the coil mounting hole [ only one per coil] slips over that has a clip connector for coil ground.
I doubt this to be the problem because , once the top inspection plate is secured, the plate mounting screws also go through the coils and ground/secure them.
Changing these 3 boots may/may not solve your problem, but are worth the $$$ and time in eliminating the possibilities ....