Page title starting with L creates a nonfunctional diagram page

Steps to reproduce:
1. Create a diagram page
2. Name it with a word starting with "L"
3. Click on Create.

Expected result: a new diagram page appears with editing options available.
Actual result: a new diagram page appears with a pop up error as in the image below.

4. Close the error pop up.
5. Save&View the page.

Result: the saved page includes a continuous loading loop, with the diagram not being visible.