Same. Sounds very much like a placebo to me. I've been trying to do all sorts of trickery ever since this stopped working properly and nothing would work consistently.
I was thinking the same but, after trying for a while, I am sure the above stop and slow-step method works. I was told about this method in-game by a guild-mate before this thread. I tried few times and gave up. After seeing the same mention here, I gave it a good try on all my characters. Right now, I do not have any tangled crops in all my 6 characters. In addition to what is mentioned above, you should try focusing on finding that point where the vine breaks. Once you have an idea where that is, try to take very small step before reaching that point. Be patient and wait for a bit (try different waiting period) before taking another step. It might take multiple tries and the vine might get bugged once in a while with that dust blowing type animation showing up. Keep on trying. The success rate is much much higher.
Edit: I can confirm that the slow stepping method works 100%. Actually it's less about slow stepping and more about finding that exact distance. It's just that moving in tiny steps near that sweet spot increases chances of getting it right. Sometimes you can get lucky bug and crops untangle without having to do this.
This garbage led me to stop farming, all the so called tricks don't work worth a damn, harvesting and planting 16 farms with these damn tangled weeds takes well over an hour. It's ridiculous.