Just replaced an old Armitage shanks Freeflow syphon on a close coupled loo, which included the pictured insert in the outlet pipe. I didn’t think much about it when I replaced the the Freeflow with a Skylo syphon. However, the toilet doesn’t now flush properly, the bowl filling high and emptying slowly; almost like it’s blocked - but nothing has changed, only the swapping of the syphon and removal of the mystery part. Any ideas before i dismantle it again?? Do Skylo syphons have a slow throughput compared to the Freeflow? And does this mystery part have any affect? Thanks in advance.