I'm translating a page with an accordion from the Otter Blocks plugin.
Although the title appears in the WPML editor, it is not translated on the pages.
Welcome to the WPML support forum. I will do my best to help you to resolve the issue.
For your kind information, the *Otter – Page Builder Blocks & Extensions for Gutenberg* plugin is not included on the WPML official compatibility list for the Plugins - https://wpml.org/plugin/. It does not mean that this plugin is not compatible with WPML, but our compatibility team has not tested it yet.
Please add the following language configuration code in WPML>>Settings>>Custom XML Configuration tab and make sure you are getting the expected results or not. Maybe you have to update the original language page/post to refresh the translation settings.