[BUG][NO ERRR] Shows student tried with same answer multiple times (email 10 and 9a)

[PhysicsRule]

Describe the bug
Sometimes it shows students tried 3-10 times on one problem with the same answer especially when multiple students are on at once. This happens at least 4 times per assignment. Last year etc. Student's notice when they try to get the most points possible.

Environment
When did this happen? many students on. and on 8/26/2020 to me.
Was it on production or staging?

To Reproduce
Steps to reproduce the behavior:

1. Go to '...' student login-assignment
2. Click on '....'submit (when many students logged on)
3. Scroll down to '....'
4. See error

Expected behavior

Screenshots

Desktop (please complete the following information):

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari] chrome at least
• Version [e.g. 22]

Smartphone (please complete the following information):

• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context
Add any other context about the problem here.

Should be fixed as of ed215b3