Ok...I did a LOT of exploring but NO Tungsten appeared.... :-(
But I found a solution - hope it helps others.......
(Or am I the ONLY person, that has been creating a single mega-factory over many, many months, and hence affected by the upgrade...?)
So the upgrade, DOES appear to have made changes such as removing 'Exceptional Ore' - so no more tungsten, lithium, scrap, calcite or holmium.
NEW maps will generate them, but EXISTING saves will NOT generate them as you explore new blocks :-(
It appears some recipes changes too!
Lithium is now created from lithium-brine, and holmium comes from scrap.
PLUS...I noticed that NO new biter nests generate as I explore further.
OK......the FIX.
Need to open the LUA console with [SHIFT]+[.]
Then enter the following command and click [ENTER]
/c local s=game.surfaces["nauvis"]; local m=s.map_gen_settings; local controls={"tungsten-ore","lithium-brine","scrap","calcite","sif-enemy-base"}; for _,n in pairs(controls) do m.autoplace_controls[n]={frequency=1,size=1,richness=1}; m.autoplace_settings.entity.settings[n]={frequency=1,size=1,richness=1}; end; m.autoplace_settings.entity.settings["holmium-ore"]={frequency=1,size=1,richness=1}; s.map_gen_settings=m; game.player.print("Added Space Is Fake migration autoplace fixes")
This adds the missing configs for tungsten, lithium-brine, scrap and calcite and biter nests.
When exposing newly explored blocks 'now', these elements will randomly be generated :-)