You hear a click because your samples are recorded for a specific time and then suddenly stop, sot it's likely going to click.
If you are not going to sustain loop your samples (i.e. to add infinite playing length, with amp envelope 'release' giving a nice fade upon release), you can edit the sample to add fix the click (e.g. add a fade) or use the amp envelope on your keygroups to fade out your samples (set 'ALL' keygroups, set amp sustain to 0, decay to taste).
Note that adding 'tail' will record whatever audio plays when the note you are recording is 'released' by autosampler. This could add a nice fade, but it does depend on the patch itself (for example the patch might be set to 0 release in your synth, hence will still probably click). And if the patch has a long release time then the tail setting must reflect this. You can of course edit your patches appropriately before recording them, setting a suitable release time in your synth's amp envelope (and remember to disable any ambient FX in your synth).
https://www.mpc-tutor.com/mpc-bible-tut ... tosampler/