@Florian VARENNE
Offline discussion update/resolution:
Discussed issue with our team, "We do update the cipher suite for TLS connections on DCs but haven’t really looked into LDAPS. We obviously need to look into this more since we don’t recall ever receiving a request to change LDAPS cipher suite but changing one off config for you would be extremely hard to do. And allowing to secure the ldaps cipher suites via a feature would take time and probably won’t be prioritized immediately.
Not to mention we would have to get security clearance about any potential cipher suite updates that are not already published as secure by Microsoft (like we do for SSL/TLS channel)"
As changing Cipher suites was not possible at Azure. @Florian VARENNE followed alternative approach to resolve the issue VPN site to site with the Stormshield and Azure then a simple LDAP without TLS through the VPN
Please remember to "Accept Answer" if answer helped, so that others in the community facing similar issues can easily find the solution.