If this just started happening after an update to VS then you should really report it to MS using Report a Problem. In almost all cases they will recommend the following steps.
- Reset your settings to default (ideally after backing up your existing settings). Then try again. If it works then your settings are messed up with the changes. Reapply your settings again to see if the fix remains.
- If you are using an extensions then disable or uninstall them and try again. If the problem goes away then reinstall the extensions to see if the problem remains fixed or is reintroduced by one your extensions.
- Repair the VS installation (never works for me).