[Masteroshi430]

I workarounded that by recalling the same function 50ms later if GetMapFilterType() == 0 in two places but I don't really understand what is really going on:

local function ZoneCheck()
    if GetMapFilterType() == 0 then zo_callLater(ZoneCheck,50) return end

function FyrMM.SetMapToPlayerLocation(stealth)
    local changed = false
    if not Stealth then
        if Fyr_MM:IsHidden() then return end
    end
    if GetMapFilterType() == 0 and (FyrMM.SV.WorldMapRefresh or stealth) then zo_callLater(FyrMM.SetMapToPlayerLocation,50) return end

Something is apparently going on during loadscreens, some controls had SetHorizontalScroll() and SetVerticalScroll() to be set again at some point in the code in order to be displayed on screen after a loadscreen like if they were set to nil during the load screen.