it sounds like some are not clear 100% on how a password manager works in general.
whether your vault is stored locally or in the cloud, it is encrypted. meaning you have to put in your master password and any other 2FA needed to access your stored passwords.
if it is stored in the cloud, then it does not matter what user is logged in at the moment whether it is a standard or admin user. if the software is present to access the vault and they know the master password, then they have access to the vault and all contained within.
same if it is stored locally, unless the vault is itself on an encrypted drive, then anyone can get to the file to access it but again would need the software and master password to access any of the contents. without it, it is just an encrypted file using space on the drive.
so a user, admin or otherwise, trying to "snoop" would need to capture your password to be able to do anything at all. a keylogger or other type thing would be needed. that's not a windows security issue really. there is not really anything just having admin rights automatically would do to just magically allow access to your vault. that's the whole point of the manager, to keep your data so only you can get to it if and only if you have the master password and any other 2FA needed.
that's also the con of a manager. if you forget your master password or lose access to the 2FA device, then you lose access to your vault and there is NOTHING anyone can do about it since by its very nature, you can't crack the master password to get access. that of course assumes you use a truly secure password long enough and with varied characters to make it impossible to crack at this time.