Hi @John kim,
Welcome to the Microsoft Forum for technical support.
After my testing, clicking reply all on my device does not cause the situation you mentioned.
Based on your description, I have a few questions for you to confirm:
- Have you configured two accounts in the same Outlook client, does the other account have the same problem?
- What is the specific version of your Outlook client? Make sure it's the latest version by navigating to File > Office Account > Update Options > Update Now.
- Does the problem occur on the Outlook.com web client?
- Has your email address been added to the distribution list? Is this distribution list included in all reply recipients? If only the mobile app has this issue, it may be an issue with the app itself. I suggested you open a case in a separate forum.
Please feel free to contact me if you have any queries.
Best,
Jake Zhang