Cannot delete some custom user certificates on Android 10

I have added user certificates, but Android do not let me delete most of them. How did I add the certificates: - Open the setting drop down menu - Go to *Biometrics and Security* -> *Other Security settings* -> *Install from Device Storage* - Enter the pin - Type a name for the certificate - Choose if it is used for *VPN and apps* or *Wi-Fi* 1- If I add it as a *Wi-Fi* cert, then I can see it in the list from the *User certificates* menu, but it is not present in the list from *View Security* certificates. This kind of certificate do not let me delete the certificate later. 2- If I add it as a *VPN and apps* cert, then I see it both in the list from the *User certificates* menu, and also in the list from the menu *View security certificates*, at the tab USER. Only from this tab I can delete the certificate. I cannot delete from the menu *User certificates*. In both scenarios the CA certificate has no effect. The certificate has been tested in other different machines, working fine, and it has the flag *CA=TRUE*. Then, my questions are: a- How to delete the *VPN and apps* certificates I've ended up adding many duplicates b- How to get the CA certificate to properly work? I am testing it with Firefox, Firefox Focus, and Chrome. *Android version 10, running on Samsung Galaxy note 9.*