Nether Portal doesn't trigger the sound when the player steps in and exits the portal. It only plays the sound when it is activated. It started at an unknown time.
I tested it out. Turns out that your best bet to get wither skulls would have an enchanted sword of Looting III. Looting III is the most reliable than Looting I and II. Looting III raises the rare drop chance to 5.5%. With that said, try that out.
It will take awhile if you want a stone sword. I got one on a few tries. I tried Looting III for a wither skull, and it worked the first time. Just be patient and you'll receive your wither skulls.
Austin Lee
BDS-5067
MC-183443
MCL-14052
I got the same thing too. It only works fine whenever I minimize the window. Painful.
I tested it out. Turns out that your best bet to get wither skulls would have an enchanted sword of Looting III. Looting III is the most reliable than Looting I and II. Looting III raises the rare drop chance to 5.5%. With that said, try that out.
It will take awhile if you want a stone sword. I got one on a few tries. I tried Looting III for a wither skull, and it worked the first time. Just be patient and you'll receive your wither skulls.
This was infuriating when I couldn't enchant a dropped bow from a skeleton.