I use a WiFi Shield model B and an update to 19.5.2 was possible.
But I can not select the firmware 19.5.4 from the dropdown box in the WiFi Fireware/Certificates Updater.
In the a tools folder .... 19.5.4 is only one file: m2m_aio_3a0.bin available.
(WiFi101-FirmwareUpdater-Plugin/firmwares at master · arduino/WiFi101-FirmwareUpdater-Plugin · GitHub)
Is an Update to 19.5.4 possible or available?