[myrroddin]

Okay, this is bizzare; I was wrong: it isn't WoD zones, it is the final check to assign world zone data. No matter if I use:

if type(watchedFactionID) ~= "number" then ...

Or if I use

if not watchedFactionID then ...

Both of these fail, or at least are somehow assigning a value of 0 or nil to watchedFactionID. I have no clue why either of those if statements are behaving like that.

Here is my updated function SwitchedZones() with the faulty if statement on line 82 below.

-- Player switched zones, subzones, or instances, set watched faction
function RepByZone:SwitchedZones(event)
    if not db.enabled then return end -- Exit if the addon is disabled
 
    -- Possible zoning issues, exit out unless we have valid map data
    local uiMapID = C_Map.GetBestMapForUnit("player")
    if not uiMapID then return end
 
    if isOnTaxi then
        if not db.watchOnTaxi then
            -- On taxi but don't switch
            return
        end
    end
 
    -- Some data may not be available because of the specialty zone functions, get something until a full data update refreshes things
    instancesAndFactions = instancesAndFactions or self:InstancesAndFactionList()
    zonesAndFactions = zonesAndFactions or self:ZoneAndFactionList()
    subZonesAndFactions = subZonesAndFactions or self:SubZonesAndFactionsList()
 
    if event == "BODYGUARD_UPDATED" then
        -- This is a custom event
        bodyguardRepID = self:GetActiveBodyguardRepID()
    else
        -- bodyguardRepID might still be nil if there is no bodyguard
        bodyguardRepID = bodyguardRepID or self:GetActiveBodyguardRepID()
    end
 
    -- Set up variables
    local _, watchedFactionID, factionName, isWatched
    local hasDungeonTabard = false
    local inInstance, instanceType = IsInInstance()
    local whichInstanceID = inInstance and select(8, GetInstanceInfo())
    local parentMapID = C_Map.GetMapInfo(uiMapID).parentMapID
    local subZone = GetMinimapZoneText()
    local isWoDZone = self.WoDFollowerZones[uiMapID] or (self.WoDFollowerZones[uiMapID] == nil and self.WoDFollowerZones[parentMapID])
 
    -- Apply instance reputations. Garrisons return false for inInstance and "party" for instanceType, which is good, we can filter them out
    if inInstance and instanceType == "party" then
        hasDungeonTabard = false
        -- Certain dungeons do not benefit from tabards
        if self.tabardExemptDungeons[whichInstanceID] then
            return
        end
        -- Process faction tabards
        if db.useFactionTabards then
            if tabardID then
                watchedFactionID = tabardID
                hasDungeonTabard = true
            end
        else
            -- We aren't watching faction tabards
            hasDungeonTabard = false
        end
    else
        -- We aren't in a party
        hasDungeonTabard = false
    end
 
    -- We aren't in an instance that supports tabards or we aren't watching tabards in the dungeon
    if inInstance and not hasDungeonTabard then
        watchedFactionID = instancesAndFactions[whichInstanceID]
    end
 
    -- Override in WoD zones only if a bodyguard exists
    if isWoDZone and bodyguardRepID then
        watchedFactionID = bodyguardRepID
    end
 
    -- Process subzones
    if db.watchSubZones then
        -- Don't loop through subzones if the player is watching a bodyguard rep
        if isWoDZone and bodyguardRepID then return end
 
        -- Battlegrounds and warfronts are the only instances with subzones
        if inInstance and instanceType ~= "pvp" then return end
 
        -- Get our subzone data
        if subZone then
            watchedFactionID = CitySubZonesAndFactions[subZone] or subZonesAndFactions[subZone]
        end
    elseif not watchedFactionID then
        if (isWoDZone and bodyguardRepID) or inInstance then return end
        -- Get world zone data or the character's default watched faction
        watchedFactionID = zonesAndFactions[uiMapID] or db.defaultRepID
 
        self:Print("DEBUG: watchedFactionID:", watchedFactionID)
    end
 
    -- WoW has a delay whenever the player changes instance/zone/subzone/tabard; factionName and isWatched aren't available immediately, so delay the lookup, then set the watched faction on the bar
    C_Timer.After(db.delayGetFactionInfoByID, function()
        if type(watchedFactionID) == "number" then
            -- We have a factionID for the instance/zone/subzone/tabard or we don't have a factionID and db.defaultRepID is a number
            factionName, _, _, _, _, _, _, _, _, _, _, isWatched = GetFactionInfoByID(watchedFactionID)
            if factionName and not isWatched then
                C_Reputation.SetWatchedFaction(watchedFactionID)
                if db.verbose then
                    self:Print(L["Now watching %s"]:format(factionName))
                end
            end
        else
            -- watchedFactionID is not valid because there is no factionID for the instance/zone/subzone/tabard or db.defaultRepID is not a number
            C_Reputation.SetWatchedFaction(0)
        end
    end)
end