When a Guild loses all of its bids for Guild Trader, the previous week's Trader is NOT cleared from the Guild UI.
It therefore is
impossible for this Guild to Hire a vacant Trader.
As you can see, the Guild UI believes that UESP still owns the Trader Jee-Ma in Orsinium.

However, Jee-Ma is owned by Made In Canada right now, NOT UESP.

Therefore when a Guild Officer finds a vacant Trader, they are unable to Hire and receive the message "this guild has already hired Jee-Ma".

I don't think I can even begin to explain how angry and upset I am that this bug still persists in the game,
a full calendar year after I first reported it.
Guildmaster of the UESP Guild on the North American PC/Mac Server 2200+ CP & also found on the European PC/Mac Server 1700+ CP
These characters are on both servers:
Alix de Feu - Breton Templar Healer level 50
Brings-His-Own-Forest - Argonian Warden Healer level 50
Hrodulf Bearpaw - Nord Warden Bear Friend & identical twin of Bjornolfr level 50
Jadisa al-Belkarth - Redguard Arcanist looking for a role
NA-only characters:
Martin Draconis - Imperial Sorceror Healer (Aldmeri Dominion) level 50
Arzhela Petit - Breton Dragonknight Healer (Daggerfall Covenant) level 50
Bjornolfr Steel-Shaper - Nord Dragonknight Crafter & Not-Much-Damage Dealer (Ebonheart Pact) level 50
Verandis Bloodraven - Altmer Nightblade Healer & clone of Count Verandis Ravenwatch (Aldmeri Dominion) level 50
Gethin Oakrun - Bosmer Nightblade Thief & terrible Tank (Ebonheart Pact) level 50