12 out of 55 have no carbonation. HELP

12 out of 55 bottles didn't carbonate. Left them for over 21 day in the bottle before opening.

The only thing I can think of is when I added the priming sugar I didn't transfer to a bottleing bucket but just bottled out of the secondary vessel.

The last batch I put the priming sugar solution in the bottom of the bottleing bucket then transfered the secondary to it. Is this the proper way to do it?

...so you added the priming sugar directly to your secondary fermenter then bottled from that?

my guess it that had incomplete mixing of priming sugar with beer before bottling leading to inconsistent priming.

yes, the correct way is to dissolve the priming sugar by boiling in a cup or water, let cool and dump into bottling bucket. Then siphon the beer onto of the priming sugar to mix it all up..then bottle.

The point of adding priming sugar to the bottling bucket before racking into it is that it ensures good mixing. You can't exactly mix it too well in secondary, or you'd stir up all the sediment you waited weeks to have settle out... so yes, you should be racking to a bottling bucket first.

Another FNG mistake!
Oh well..... That's how we learn sometimes!

That would also explain why some were over carbonated.

Its all good, live an learn