Admin boundaries, strange results on parishes

[lin-d-hop]

Describe the bug
I noticed this zoomed in on Bromsgrove, but it seems to extend across the country.

The ward and parish shapes look like they should overlap, but are offset. The ward data looks correct based on road lines. The parish data looks offset.

Can we find out if this is a problem with the source data or our implementation please?
If an issue with the source data, can we assess if this is known, or file a bug report if not?
Is there something we can do to correct this in house?

To Reproduce
Steps to reproduce the behavior:

1. Turn on wards and parish data layers
2. Zoom in to an area with both eg Bromsgrove
3. See offset

Expected behaviour
Where ward and parish lines are the same, the lines on the map should overlap

Context (please complete the following information):

• Device: [e.g. iPhone6] PC
• OS: [e.g. iOS8.1] Ubuntu
• Browser [e.g. stock browser, safari] Chrome
• Version [e.g. 22] Production May 10th