Steps to reproduce:
Example:
1. Let's suppose we have 4 min intervals for Internal Checks for some time
2. We've updated this interval from 4 min to 1 min.
3. Old data (with 4 min intervals) on historical graph is separated dots. Fresh data (1 min intervals) in graphs is normal continuous lines as it's supposed to be.

Result:
See screenshot...

Expected:
Graphs should be continuous lines as usual despite of changing update intervals.