Blue - hmmmm, not a good thing! First off, check all ammo in that batch - in case the neck hold and taper crimp is insufficient. This should not normally happen unless one particular round is first into chamber every time you re load gun.
Take a look at your feed ramp - see if it could usefully be Dremel buffed to mirror finish - also check the mag you used against others. Are feed lips distorted or abnormal - allowing top round to sit with too little ''cock-up''. Did you drop slide slowly or quickly - usually we sling-shot to ensure battery but - again wondering about that re any mag issue.
Further thought - if in fact mag lips allow too much cock-up - again that could be bad - worse even as bullet gets slammed on top of chamber, then still, in this case feeding in fully, to battery I assume.
New gun? Old gun? Make? . How much thru it? - any previous issues?
Just thinkin out loud for now.