Kohler Cimarron Toilet Any Plumbers Out There? I Need Help With A Plumbing Issue In An Older (1950's) House. My Toilet Keeps Clogging

Any plumbers out there? I need help with a plumbing issue in an older (1950's) house. My toilet keeps clogging - kohler cimarron toilet

A few months ago I bought a house that was built in the 1950s. I have found in a bath of Cimarron Kohler, who came highly recommended. I had nothing but trouble. The toilet is clogged all the time (even when there is nothing inside). I replaced all the plumbing pipes with ABS and even tried another bathroom ... Toto Ultramax book. The first flushing toilet was fine, and does the same. Of course, the problem is 2 new toilets and I replaced all the pipes. Other ideas that could be causing this problem? I am so frustrated: (