"This Month" time range doesn't update if app was opened last month

**Describe the bug**
Sorry this is going to be pretty horrible...

The "This Month" option on the cost plot when a batch account is selected doesn't update if the month changes while the app is open.

**To Reproduce**
Steps to reproduce the behavior:
1. Open Batch Explorer in September
2. Go to a batch account
3. Select "This Month" on the cost view
4. Get September data
5. Wait until October (leaving Batch Explorer open)
6. Go back to the batch account, select "This Month" on the cost view
7. Get data for September

**Expected behavior**
Data shown for October

**Version (please complete the following information):**
- OS: Windows
- Version 2.3.1 stable