URL: https://covid19uk.live/

Browser / Version: Firefox Preview Nightly 200505 (77.0a1-20200503093615)
Operating System: OnePlus6 (Android 10) 1080 x 2280 pixels (~402 ppi pixel density)
Tested Another Browser: Yes Chrome

Problem type: Site is not usable
Description: Missing items
Steps to Reproduce:

1. Access https://covid19uk.live/
2. Scroll down to the "Data" section's chart.
3. Tap the "Full Chart" button from the bottom of the chart.
4. Switch the device to landscape mode as suggested.
5. Observe the chart.

Expected Behavior:
The chart is displayed in landscape mode.

Actual Behavior:
The chart is not displayed.

Notes:

1. The issue is not reproducible on Chrome 81.0.4044.117
2. Screenshots attached.

Watchers:
@softvision-oana-arbuzov
@cipriansv
sv;

This is how the page looks on Firefox Nightly:

And this is the page on Chrome:

From webcompat.com with ❤️