Page Turner doesn't work when using iPad Pro 12.9 3rd Generation 4th Generation.

I heard that it sometimes works on iPad Pro 11 inch, iPad Pro 12.9 inch 5th generation M1, but it doesn't work on iPad Pro 12.9 inch 3rd generation 4th generation. I thought it might be a compatibility problem with the page turner, so I tested 4 units for each different type of page turner, but it doesn't work. A typical example is that it does not work with iRig Blue Turn products.