Hi Simon Norton,
Thanks for using Microsoft Q&A !!
Are you updating the configuration in configuration settings?
As per the documentation, the configuration - MaximumStatelessVariableSize
needs to go to host.json and not in the app settings, as mentioned in the below documentation - Edit runtime and environment settings for Standard logic apps - Azure Logic Apps | Microsoft Learn.
Below is a sample host.json for increasing the variable size limit from 1024 to 2048 characters.
Please let me know if you have any questions.
Thanks
Saurabh
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