Adobe Campaign Standard Selects Losing Variant from A/B Tests

[AzizMalek]

I created an email campaign on ACS with A/B subject lines where it'll send the test for 10% of the audience for each variant then send the remaining 90% to the winning variant based on open rate. 

For some reason, Adobe keeps selecting the losing variant as a winner and sends the remaining to it. Any idea what may be the cause behind this? 

[mmbb110]

Can you let us know if you have manual winner send or automatic? Also pleaseThe test must be at least one hour in order for all of the tracking data to be collected and correctly taken into account to select the winning variant. check

[AzizMalek]

Yea its Automatic and the testing period is 1 hour

[mmbb110]

I have never encountered such thing before, can you set up a new test altogether once again and check if turns out to be similar issue? I think it could be one off transient errors.