AMP-AUTO-ADS not working

## What's the issue?
AMP-AUTO-ADS not showing on AMP pages (both on mobile and desktops)
## How do we reproduce the issue?
Please provide a public URL and ideally a reduced test case (e.g. on jsbin.com) that exhibits only your issue and nothing else. Provide step-by-step instructions for reproducing the issue:

1) Visit https://fknol.com/uk/market-cap-ftse-100-index-constituents.php
2) The page is perfect AMP page (test for AMP at https://search.google.com/test/amp),
3) Despite using the correct adsense code in between the head tag and immediately after the body tag, it still does NOT show any ads.

Steps as above.

Also, seeing the following error/warning in Chrome Console:
CustomElement] Cannot resize element and overflow is not available ​…​​
hb @ log.js:258

I am not setting these anywhere...its all getting picked automatically. So what's the fix

## What browsers are affected?

All browsers

## Which AMP version is affected?
All

Start by visiting the reported URL and reproducing the AMP validation result and Chrome Console warning for the amp-ad element. Trace the warning through the AMP runtime entry point identified by the console and determine the conditions under which the ad remains at height 0; done means the reported page displays its AMP auto ads without that failure.

Written by the indexing model from the issue text.