To reproduce:
- Open a history plot, click [-] a few times until the x axis shows more than 7 days.
- Scroll to the past (left)
- Click "Jump to current time" (the triangle)

Expected result:
The upper limit of the x axis is at the current time and the lower range is now - whatever range you had before 
(>7d)

Actual result:
The upper limit is the current time, the lower limit is now - 7d

(The interval seems unchanged if the range was < 7d before clicking "Jump to current time")