Clear BLE service and characteristics cache

Hi, we're having trouble with a device that changes its services to do firmware updates and does not implement the Service Changed characteristic. I understand that the iPhone caches the services, is it possible to clear this cache, or is it known how long does it last? We unfortunately cannot reset the iPhone as I've seen suggested, as this is the users' phone I'm talking about.

Thanks

Clear BLE service and characteristics cache
 
 
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