Soundstage

I would have a full electron microscopic spectral analysis completed on the crystals in the metal of each cable, but I would first want to know the square root of the exact temperature (celsius) at which cryo-freezing took place - that will then give you proper wire burn-in and saturation quotients. And the arrows - ALWAYS pay attention to the arrows - especially on the interconnects...

I’m English, and it’s definitely swap.
maybe the OP had a slight and temporary blockage in his right ear that coincided with his cable swap.

Simple way to test; use a Left//Right/Center voice test track . They are readily available for download. You will know immediately wether the soundstage is or is not skewed.  Center image is a range, so play with positioning.  If you have L/R balance controls, work with them.

There can be a bad connection inside one of the connected devices.

Get a VOM and clip leads. Measure conductor and shield end to end on the interconnects while vigorously wiggling the connectors. Resistance should remain ZERO.

Repeat with each connector measuring between conductor and shield. Do both ends of the cable. Resistance should remain infinite.

If the above are true, problem is internal. DO NOT wiggle connectors to a power amp. You run the risk of dumping full power into the speakers. Use a dummy load. 

Hate to say it but maybe your hearing?  I started having a problem over this past winter where the right side seemed slightly muted at times.  Soundstage seemed shifted to the left.  Barely noticeable but frustrating.  It took maybe a month or so to realize that I had some tinnitus starting in the right ear.  Nothing wrong with my gear/setup.  

How loud do you listen?  Could be after a few hours you start having auditory issues