WebEx Audio with WebProtection

Dear Forum,

we encounter issues with WebEx Audio. We can open a WebEx but Audio is blocked.

We have the UTM as our transparent Proxy. We are not allowed to bypass, so I created the following exceptions:

^https?://([A-Za-z0-9.-]*\.)?akamaicdn.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?lp.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?webex\.com/
^https?://([A-Za-z0-9.-]*\.)?meetingsln.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?ed1chcbmm100.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?ed1txcbmm80.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?ed1hkcbmm70.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?imln6\.ciscowebex\.com/
^https?://([A-Za-z0-9.-]*\.)?ed1sjcbmm10.webex\.com/
^https?://([A-Za-z0-9.-]*\.)?dms-eu.webexconnect\.com/
^https?://([A-Za-z0-9.-]*\.)?webex.tt.omtrdc\.net/
^https?://([A-Za-z0-9.-]*\.)?webexconnect\.com/
^https?://([A-Za-z0-9.-]*\.)?wbx2\.com/
^https?://([A-Za-z0-9.-]*\.)?ciscospark\.com/
^https?://([A-Za-z0-9.-]*\.)?localytics\.com/
^https?://([A-Za-z0-9.-]*\.)?rackcdn\.com/
^https?://([A-Za-z0-9.-]*\.)?clouddrive\.com/
^https?://([A-Za-z0-9.-]*\.)?crashlytics\.com/
^https?://([A-Za-z0-9.-]*\.)?js-agent.newrelic\.com/
^https?://([A-Za-z0-9.-]*\.)?bam.nr-data.net\.com/
^https?://([A-Za-z0-9.-]*\.)?quovadisglobal\.com/
^64\.68\.(9[6-9]|1[01]\d|12[0-7])\.([1-9]?\d|[12]\d\d)$
^66\.114\.(16\d|17[0-5])\.([1-9]?\d|[12]\d\d)$
^66\.163\.(3[2-9]|[45]\d|6[0-3])\.([1-9]?\d|[12]\d\d)$
^170\.133\.(12[89]|1[3-8]\d|19[01])\.([1-9]?\d|[12]\d\d)$
^173\.39\.(22[4-9]|2[3-9]\d)\.([1-9]?\d|[12]\d\d)$
^173\.243\.(\d|1[0-5])\.([1-9]?\d|[12]\d\d)$
^207\.182\.(1[6-8]\d|19[01])\.([1-9]?\d|[12]\d\d)$
^209\.197\.(19[2-9]|2[01]\d|22[0-3])\.([1-9]?\d|[12]\d\d)$
^216\.151\.(12[89]|1[3-5]\d)\.([1-9]?\d|[12]\d\d)$
^114\.29\.(19[2-9]|2[01]\d|22[0-3])\.([1-9]?\d|[12]\d\d)$
^210\.4\.(19[2-9]|20[0-7])\.([1-9]?\d|[12]\d\d)$
^69\.26\.(17[6-9]|18\d|19[01])\.([1-9]?\d|[12]\d\d)$
^62\.109\.(19[2-9]|2\d\d)\.([1-9]?\d|[12]\d\d)$
^69\.26\.(16\d|17[0-5])\.([1-9]?\d|[12]\d\d)$

Any Ideas so far what else we can do?