I've not seen an integration for this CRM, but we are currently engaged with building 3 different CRM integrations at the moment. If you need some help, we can offer some advice on the process and some of the pitfalls to watch out for.
I've seen a bunch of other integrations with 3cx but not with CiviCRM. Took a look at the how-to here: https://www.3cx.com/docs/crm-integration/ and it's really impressive. Does this work 100% of the time?