Freeland1 gear selection problem

Hi there.
I am new to forums so apologies if I get anything wrong.
Anyone had trouble with a Freeland1 suddenly being hard to change gears while driving but issue is intermittant. Have re-built engine and fitted new clutch at same time, all was well while running in engine done a hundred miles with no gear trouble then suddenly hard to change up or down but not all the time. Master and slave cylinders working fine. Any ideas?
Thank you.

What engine?

If 1.8K, problem would be consistent with a failing clutch master cylinder, air in the "sealed" clutch system or cracked or loose slave cylinder bracket. How do you know the cylinders are working OK?

Problem solved - loose slave cylinder mounting bracket.
Thanks for the reply though