Cannot read property 'ampdoc' of undefined on Amp-next-page

When developing the amp project page, I use the **amp-next-page** extension version **1.0** (https://github.com/ampproject/amphtml/tree/master/extensions/amp-next-page/1.0). Faced such a problem: if you quickly scroll up/down, then you get duplicate page separators (https://clickio.gyazo.com/f9d2fec4421d5bdf8f1110228d23fa68 ), separators are inserted into the page, but the content of the loaded pages between them (https: //clickio.gyazo. com/ c2150d12ea54633d73ac89802fd52d42 ). In the console of the page, you can see the following errors: https://clickio.gyazo.com/0107e6d4a79b4488848fbb337b020a10. At the same time, no page loading errors are observed in the Network tab: https://clickio.gyazo.com/287aa9f02f5c87d262a0b2021e68cdc7
If you scroll the page at low speed, then such errors still appear in the console (https://clickio.gyazo.com/ddb38830be6d1b6790648f89bf3b4a28 ), but this happens less often, and separators are not duplicated. The general structure of the page looks as it should be: loaded page, separator page, page, page separator, etc.
I did not find any information on how to solve these errors on the Internet, so I am writing here, hoping to get help.
The **amp-next-page** library version **0.1** was previously used on this page and no such problems were observed.

The problem is reproducible in such browsers: **Chrome (v84.0.4147.125)**, **Vivaldi (3.2.1967.47)**
AMP version: **2007302351001**

The page where you can see:
https://amp.clickiocdn.com/a/www.mensagensdebomdia.com.br/bom-dia-colorido?lx_nocache=1&cl_cachebuster=34573465934534&cldaemon=develop
If you need more information, I will provide it upon request.

Start with extensions/amp-next-page/1.0 and reproduce the issue at the provided page URL using rapid and slow scrolling in the listed browsers. Inspect the console error involving ampdoc alongside the page-separator behavior; done means pages load in order without duplicate separators or missing content.

Written by the indexing model from the issue text.