recurrent error 403

Hello
I have installed the latest version 7.11.0 of suite CRM on a shared web hosting.

First everything looked perfect, then the problems started! I couldn’t log in with a new user. Probably the password will not be accepted. As a solution I could define a new one with “Forgot password”, with which the login works.

But now I have the problem that the page is not accessible again and again. ERROR 403: Sometimes only with a web browser, which is completely senseless. With Google Chrome the error appears, with IE11 not. The error then disappears on its own. Sometimes faster. Sometimes it takes forever.

Does anyone have an idea where these problems could come from?

Regards Roland

For the user login problem I found the bugfix!
https://github.com/salesagility/SuiteCRM/pull/6780