Not able to silence entities/checks for a specific duration #412

Expected Behavior

Silence should be created for the selected entity/check

Current Behavior

Silence is not being created

Possible Solution

? Since this is SPA may be issues could be on the code itself

Steps to Reproduce

1. Select an entity that you would like to silence
2. Click "Silence"
3. Toggle "Expire after a fixed duration"
4. Select any amount of seconds.
5. Click "Create"
6. Silence being created modal being shown, but there is no actual silence being created.

Context

This issue affects our environments where we are not able to silence the checks for the specific duration in our maintenance windows.

Your Environment

• Sensu version used (sensuctl, sensu-backend, and/or sensu-agent): - sensu-backend - v6.5.5, sensu-web - v1.2.0 ( tried v1.2.1 and v1.1.0)
• Installation method (packages, binaries, docker etc.): - docker
• Operating System and version (e.g. Ubuntu 14.04): 4.14.276-211.499.amzn2.x86_64 Alpine Linux v3.15
• Browser used - Chrome, FF, Safari