Wi-Fi is disconnected when SSID broadcast is disabled

Hi,
When I disable SSID broadcast, the Wi-Fi connection of my smartphone is disconnected. As soon as I enable SSID broadcast, my smartphone's Wi-Fi is connected. The phone manufacturer insists that SSID broadcast is not necessary for the Wi-Fi connection. I don't have this issue with another device (Roku), which stays connected after disabling SSID.

My wireless network settings are:

- 2.4 GHz (my phone doesn't support 5 GHz network)

- Channel: Auto (Current: 1)

- Mode: Up to 300 bps

Could anyone advise what may be causing this issue and what I should try to fix this issue? Thank you.