Hello,
I seem te be having a similar problem,
yesterday my alarm started displaying the same issue. Only it had been working perfectly for the past 5-6 years.
The problem now seems that my installer seems to have gone out of business and nobody want to touch this old thing.
I'm capable of doing a reboot (disconnect mains and battery) myself but am wondering if this wil have any influence on the problem.
Regards Stijn