Wi-fi hotspot doesn't transmit data
Wi-fi hot-spot doesn't transmit data after startup or just doesn't work properly, however it is possible to connect to it. After turning it off and on it changes it's network name and there is no possibility to change it back at Settings -> Wi-Fi.
Solution 1:
To change network name back use nm-connection-editor.
To make wi-fi work again run Settings -> Wi-Fi -> ≡ -> Connect to Hidden Network... and select appropriate hot-spot connection.