Banana plug recommendations

I own a 5 meter set of Acoustic BBQ speaker cables terminated with KLEI Classic Harmony bananas at the amp end and large spades at the speaker end.  At the time I bought them, Bill Dion strongly recommended the KLEI's instead of my previous screw-ons WBT's because they sounded the best to him of all the bananas that he offered. He wasn't wrong about sound quality. The cables sound magnificent, although, of course, I haven't tried them with any other connectors. I have emailed Bill to ask his recommendation for a substitute, but he is out of the cable business and I won't bug him if he doesn't care to respond or doesn't have other recommendations. 

I just got a new Apollon Audio amp and have found that one of the KLEI's is pretty loose in the standard WBT binding post socket and keeps sliding out a bit because of the long cable's weight.  As a result, I have had instances of that channel cutting out until I twist the plug further into place and get it to stick. 

I looked at that plug more closely and saw that the barrel looks visibly thinner than the others. It doesn't look damaged or anything, but it's oddly slightly smaller.  (I would attach a pic, but, now that I have it lodged in place pretty well, I hesitate to pull it out again.) 

I now think I want to reterminate the cables' amp end so that I have a more robust connection in the binding post.  

So, this is the question:  Is there another banana plug that has competitive sonic quality but that is a bit more rigid and that makes solid contact?  The KLEI sound quality seems fine, but, after a previous incident that required repairs and now this barrel issue, I am not impressed with build quality where the attached cable has some weight or not much strain relief. 

Worse comes to worst, I could be okay with adding a new set of KLEI's. (Unfortunately, it doesn't look as though I can buy just a single red plug to replace the smaller barreled one.)  I just think it advisable for something that fits more snugly and is a bit more rigid. 

I can already "hear" the naysayers telling me just to get Amazon Basics because no one can hear the difference, so I will stipulate that I might not hear the difference, myself, but humor me here.  This isn't a big ticket item and I can afford to waste the money.  In the meantime, if you have found differences in quality, I definitely am interested in your thoughts.