Anyone Having Problem With Cardas Clear Beyond XL Power Cables Falling Out Of Equipment

That reminds me, Cable Elevators https://www.musicdirect.com/best-budget-tweaks-under-99/cable-elevators-cable-supports are really just ceramic high voltage insulators used on power lines and telephone poles. Their first and best use is under speaker cables, where they make a huge improvement. Take them out, lay the cables on the floor, hear the sound stage collapse. 

But you don't have to use Cable Elevators. Any similar insulator will do. And there are a lot of them! Search eBay, where believe it or not people collect the darn things as steam punk type decoration! Whatever, they're cheaper that way, as low as $5 if you shop around, and work just as good. I just added a couple to help dress my phono interconnect and raise a few others off the floor. Would work great to support a heavy stiff power cord, and you get the sonic benefit as well. 

 First, which you probably already tried but just in case, work the cable as best you can to make it fit where you want it to go without any leftover twisting or bending torque at either end. Also at the same time see if components can be situated a little different as sometimes this alone will solve the problem.

Next step which a guy with this much already invested probably has done already is upgrade the outlet and since you know this is an issue ask about it as some do have a lot tighter fit than others. Or pull the receptacle, some of them once they are out of the wall you can get a screwdriver in there and bend the contacts a little to make for a much tighter fit.

The iec at the conditioner end at least you can shim it to fit tighter. Trim some thin wood shims, or wrap the end with something like teflon tape, whatever will make for a nice snug fit.