This thread is resolved. Here is a description of the problem and solution.
Problem: We believe that with object caching this would be resolved but it seems that wpml string translation doesn't support object caching is that correct?
Solution: In this case I would recommend you to use one of this cache plugins: https://wpml.org/faq/list-of-top-compatibility-recommendations/#cache Some of them use object caching.
Also, pleas update all outdated plugins and themes, specially WPML plugins. Outdated functionalities can cause conflicts in the code.
This is the technical support forum for WPML - the multilingual WordPress plugin.