Personal stats fail to load when a tag is present

[iokiou]

Exceptions are thrown both in regular and incognito browser modes.

Description
After completing a word test using a tag and pressing the username, the personal stats page (/account) either

• does not load at all, or
  
• loads and an error message pops up stating "Something went wrong when filtering. Resetting filters." (pop up message not visible in the screenshot below)
  

Steps To Reproduce

1. Log in
2. Create a new tag
3. Select this tag for the upcoming test
4. Start a word test of 10 words
5. After completing the test, press your username

Expected behavior
Personal stats are loaded successfully.

System

• OS:
  • Edition: Windows 10 Home
  • Version: 20H2
  • Build: 19042.685
  • Type: 64-bit
• Browser:
  • Brand: Google Chrome
  • Version: 87.0.4280.88
  • Build: Official
  • Type: 64-bit
• Monkeytype Version: v1.6.9