Blackberry 10 - Q5 - auto mute notifications after texting. (silent mode)

I've been noticing lately that my phone automatically goes to silent mode after I've sent a text. When disabling silent mode, the device remains quiet (also no vibration or led) until I reboot it. Sometimes more than 1 reboot is required.

This has been getting on my nerves, as I've been missing quite a few important texts or mails when I didn't realise my sound was turned off.

This error occurs with and without hub++

Any solutions? Is this even a known bug?

Thx in advance

No, not a known bug. Probably needed a reload of the os. Did you try that?