Please update the browser to the latest version, clear its cache (device settings - "Applications" - "Yandex. Browser" - "Memory", click "Clear cache") and restart the device. Did this help you?
It will be much better if you talk about the problems with our support team (browser menu - "Settings" - "Contact us"). The fact is that here the restriction on symbols is only 350, we will not be able to advise you qualitatively. Thank you!