Afterburner shows moderate to insane frametime spikes even if they don't reflect while playing

Please look at this: https://imgur.com/a/xkvdGeZ

Look at my framerate (Velocidad de fotogramas, it's in spanish, don't mind it) and then look at my frametimes. It does not match, yet MSI Afterburner is showing frametime spikes at the games. Mind you that I don't "feel" these fluctuations, I honestly have no idea if my GPU overclock can cause Afterburner missreadings. However, it really makes me wonder how where I have no fps drop frametime spikes can occur. I am starting to think my MSI Afterburner is missconfigured or bugged, it seems to me that these type of readings just can't be. 60 flat is 16.6 ms, no other way around it. Also, note the slight fps drop that I had near the start of the line, it was like 57-58 fps I believe and it was autosave of the game I was playing, yet MSI Afterburner shows a pretty significant spike that does not match with the fps. It's like it exaggerates the frametime spikes to an insane degree.

All of this was made with a 60 fps lock from RTSS. Weird, because often you see a flat frametime line with RTSS and the only time spikes may appear is when the game saves, new assets load or when a load screen appears.

These "reported" spikes aren't present when I play, the frame rate is: 59.9 fps at 16.6 ms, so what gives? This also happens at other games; Witcher 3 even if for me is smooth while I play and the game stutters very little or has slights fps drops, when I stop playing and look at the MSI Afterburner graph, shows insane frametime spikes of up to 120 ms or even more. This is really getting off my nerves, someone please help me. Makes me think my computer is broken

 

Thanks for the answer, may try to learn a bit on what you mentioned. I didn't mean that MSI Afterburner has bugs, I meant that I may have done something and made the program show that kind of readings.