Finally, and in the past two years most relevant I have started putting lubed cath in and moving cath down and up gently before making it all the way to bladder. It seems to me that this technique lubricates the tract pretty well. I rarely have a problem since adopting this method.
I use a 14 fr cath, it is about 16" long so I insert lubed, go down about 4-5 ", pull back up ( but don't remove) gently push back down to about 9" second time and maybe third time, go all the way down to uretha assuming you are getting no resistance. For me, each time it seems to go down with less resistence. This has pretty much solved the problem, it takes about 20 seconds. The distances above are not exact but suggest you try sliding up / down a few times and seeing if it gets easier ( less resistence) each time.
Hope it makes a difference for you.