The first instance, I never took the Followers into the Gomorrah but the disappearing Weapons Inventory affected them anyway.

1. Went to the Strip for the first time in new game.

Bought Silenced 22 from the guy selling holdout weapons. Repaired it with one I had already.

Told Boone and Ed-E to wait in front of Gomorrah.

Gave my weapons to ED-E to hold, went in to gamble. The guy at the door took my Binoculars and shovel. Gambled, came out and was given those two things back and had my Weapons Inventory tab.

Went to ED-E, he had no weapons and no weapons tab in his inventory. Boone had no weapons and no weapons tab. He didn't arm his default weapon as usual.

Went through the Strip dividing doors hoping things would reappear, they didn't. Fast-traveled and they still didn't.

Went looking for enemy to see what would happen. Fiend attacked. ED-E still had his laser. Boone put up his fists, no default weapon. ED-E dealt with Fiend.

Looted Fiend, gave ED-E spiked knuckles. His Weapons tab reappeared but only the knuckles were in there.

2. Loaded earlier save, tested at Gomorrah again. Didn't buy the holdout weapon from the guy, no gambling, took Boone and ED-E in with me. Weapons confiscated. Went right back out the door. Boone and ED-E no Weapons tab in inventory but when exiting Boone's inventory, his default weapon appears on his back. ED-E, no Weapons tab in inventory and he had Weapons before we went in.

Loaded earlier Save again. Went to The Tops. Went in and out the door, took Followers in, weapons confiscated and no problems when exiting. Didn't test other casinos.

ADDED: Loaded that earlier Save. Did another test. Left Boone and ED-E to wait at the Atomic Wrangler. Went to Gomorrah, weapons confiscated. Left, got them all back. Went back to Atomic Wranger. Boone and ED-E both missing Weapons tabs in inventory, Boone had equipped his default rifle.