Safari and Chrome lose internet connection intermittently but mail and messages are still connected
Following the Catalina update the browsers (Safari and Chrome) on my MacBook Pro lose internet connection intermittently - sometimes after 10 minutes, sometimes after a day. This happens on both WiFi and Ethernet connections. Mail and Messenger, however, are still connected to the internet.
When the browsers stop loading new internet pages (strangely those already open can still be refreshed), I cannot shut down the Macbook normally or change the user - only a forced shutdown (holding the power button until it shuts down) works.
I have searched every single post in the community, but unfortunately cannot find a solution.
This is not the WiFi or Captive Network Assistants problem that is described in other posts, so creating a new location in network preferences or renewing DHCP lease does not solve the problem.
It cannot be a network problem, since Mail and Messenger work just fine and no other devices in the house are affected simultaneously. Also, no VPN or Antivirus is installed.
My daughters' Macbook Airs have exactly the same problem after the update to Catalina.
MacBook Pro 13", macOS 10.15
