Epson wont print on any thing other than Epson paper
I cant follow your argument.
desribe the results you are getting with other stock.
I run 2 Epsons one with CISS and although some substrates are plainly not for inkjet.-that is not the printers fault
Inkjet printers squirt ink onto any substrate that will pass through.
Inkjet Gloss and matt although of various brands and basically the same and should accept the output.
Acetate is different and you do need InkJet transparency material.
By preference for example I use Ilford Galeria papers both glose,pearl and matt.
But I also use Artists watercolour papar and even gesso primed canvas for special jobs.
All of which print very well.
Try the following,in the paper set up panel select inkjet transparency for all your graphics work
Come back on this