Undercabonation problem

The first batch I made was an IPA with an OG of 1.064 and a FG of 1.022. After a week I racked to a secondary and let it go for 2 weeks before bottling. I used 3/4 cup priming sugar boiled in ~2 cups of water and racked the beer on top of the sugar in the bottling bucket. All bottles were sanitized.

Even now, after about 2 months of being bottled, the beer has almost no carbonation. I shook the bottles and listened for CO2 escaping but didn't hear anything, and all the beers tasted fine, they were just basically flat. Is it possible that there was too little yeast left over to carbonate? Any thoughts or tips are appreciated.

are you 100% sure that you kept the bottles in the mid 70s during carbonation? just because the room is in the 70s doesn't mean that where the bottles are is in the 70s. did the beer swirl around and around when you racked it into the bottling bucket? if not its posable it didn't mix right. also from what i have read if the priming sugar isn't cool enough it wont mix right. are the caps lose? grip them and try to turn them to the left or right a little. if they move its suspect.

The bottles were never at mid 70's, they were kept in mid 60's. I tested the caps and there was no wiggle whatsoever and no air escaping. Oddly enough I opened a bottle last night that had been in there for at least a month and it was fully carbonated, so now I'm even more confused.

Mid 60's will carbonate slower due to the lower temp. But it will carb eventually. Also, make sure the sugar is fully distributed in the bottling bucket by gently stirring halfway through bottling. And finally, don't measure your sugar, weigh it. It is a much more precise way. There are software programs that can help you with this in finding an appropriate weight to gallon per style, as well as the influence of temp on the beer.