LEDs are directional, bulbs are not. Maybe reversing the wires at the socket of the ones that won't work will fix it?

Some are directional. Some aren't. Also you may need to bend the prongs on the led bulb a but to get them to make better contact.

I didnt have any problems with leds with the LW3 i used to own. Make sure the bulb fits nice and snug into the socket or turn the bulb 180. Another deal with a few leds the is only 1 contact lead to each side of the 555 unlike a standard bulb which was the leads on both sides. Try bending out the lead a bit to make a better contact.