Hi there,
I've just installed the latest (26.0.32) Forge, and noticed that I can't climb on vines with it. If I start the vanilla 1.14.2 version, it works pretty well, so I can climb on it. Ladders works in both versions. I tried without any mods loaded, the bug remains. The log doesn't contain any corresponding errors.
Debug log: https://pastebin.com/n7TA1uuY