Why are payment buttons sometimes not displayed (Yandex.Money)?

Question

PHP

There is such a problem. The site podarikvest.ru has payment buttons for purchasing quests. I use the button for accepting payments from Yandex. Periodically, users complain that the buttons are not displayed. Those. The impression is as if the buttons were not loaded. It was not possible to identify any pattern (browser, device, etc.). Buttons do not appear periodically for a variety of users, this happens periodically, maybe once 3-4 days. Contacting Yandex technical support did not give any result. Maybe someone had a similar situation, if so, how did you decide what the problem was. The button is integrated in the simplest way - just a button is assembled through the Yandex constructor, and then the code is inserted into the site, and that's it.

Answer 1

Perhaps users from Ukraine, for Ukraine such a service as Yandex does not work.
I don't have a button either.

Answer 2

"Button going" as a link?