Thanks for sharing, looking into it.
Thanks for reporting @SerendipiTea! We fixed the bug and we are pushing the update later today. Should be fixed for you soon.
It is not fixed for me, Lifetime : Best Ranked MMR only shows my current MMR and not my best MMR
Could you send us a screenshot of what you see in the app and a link to your profile on our website please?
Thank you, we have found the issue and will release a fix soon.
Fix is live. Thanks!