Patch 9.3 renames T49 to T67 and introduces a new T49 which is a tier 8 light tank.
Likewise, KV-1s is moved to a different tier while keeping the same tank textual ID.
This has lead to issues in NoobMeter statistics calculation, at least, for players playing the "old T49" and having played the KV-1s.
Thank you for all your feedback so far.
We are investigating the issues and trying to fix them ASAP.