So, I have been sky wars for a few days now and until today I had a score of around 130-140 but today when I spoke in global my score was 0, I was wondering if the scores had been reset, or if this is some sort of bug.
No they did not reset, but there is 2 SkyWars portals each one is different so you might of had that score in SkyWars portal 1 and recently went into the second portal. That's why you would have 0 points try going back into the portal that you usually play in.