I have noticed a rather unfortunate glitch. I was training my Ralts, and as soon as it reached level 10, it no longer gained experience. Upon looking at its stats, it turned out it *was* gaining experience, it just required an impossible amount of experience to level up. When I was looking at all my Pokemon's stats, I had captured a Tauros, also at level 10, who also required a ridiculous amount of experience to level up. Pictures are below.
Upon further investigation, Tauros and Ralts are both in the "Slow" experience growth rate group. I have a couple of other Pokemon who did make it past level 10 (Poliwag and Eevee), and they are not in the Slow experience growth rate group (they are in Medium Slow and Medium Fast, respectively, I believe).
Well, now my Ralts is no longer usable :( I just thought I would let you know about this bug.
[Actually, it turns out I can't post links to the pictures because I haven't made more than 15 posts here. If there is any sort of workaround then let me know.]