So, after doing the Battle Quests I was spending the Exp I had just earned, and when I had around 800 left, I clicked 'Speed (750 EXP)'. Instead of going back to that page, it showed the 'Subeta is down!' one. I clicked F5 as I usually do and it shows the following:

Lusitano -655 EXP Points

Did it buy Speed 2 times? I really don't know because I never keep track of how my stats are. Has this ever happened to someone else? I'm not sure where to create this thread (Battle, Help & Questions, Problems & Bugs) so I'll just leave it here...

Yea, that can happen if you click the link too quickly as well. (Yes, you did buy it twice)

No need to worry though, it work's out fine when you get more exp.

Hm okay, good! So it'll be back to normal tomorrow :) Thanks