When I add video not from standart services, I must open it in popup window to synchronize. But it opens in just new tab without synchronizing and with blank popup window. It in Yandex Browser (last version), but not on all devices. Google Chrome is working normal. I tried reinstall Yandex Browser, it didn’t help.
And I installed extension.
Yes it’s a known problem with Yandex browser. So far I was not able to find the cause for the issue. Please use Chrome, Firefox or Edge for the moment.