Solution 1:

There are a few errors in your netplan-configuration.

  1. Duplicate network sections
  2. Duplicate version keys
  3. I do not think you are supposed to enable DHCP on the interface wlp0s20f3 but rather on the bridge only.

Like this:

network:
  version: 2
  renderer: NetworkManager
  ethernets:
    wlp0s20f3:
      dhcp4: false

  bridges:
    br0:
      interfaces: [wlp0s20f3]
      dhcp4: yes