I've completed a project in computational physics. 100% of the code and running of the code completed by me and the introduction, theory and code description in the paper written by me. Results section written by supervisor with some feedback from me.

When we put the latex together I was listed as first author on the paper, since, as my supervisor stated, I did 95% of the work. However, when the paper was submitted my supervisor listed themselves as first and corresponding author in the online submission fields (I was still first in the author list of the submitted paper - ie. in the actual latex document).

When I pointed this out to the supervisor they denied it, so I logged in to the journal account and sent a screen grab showing the status, They said that they must have made a mistake and would correct later when resubmitting (flagged for some missing documents).

Later on I got an email stating that they had submitted the documents but 'forgotten' to correct the author status but not to worry because I'm listed first in the submitted latex paper.

I'm not sure what to think here. Perhaps my supervisor is correct and it will make no difference (since I'm listed first in the latex paper) and is just winding me up. Either that or not I feel that I need to push back here, somehow without damaging the relationship.

Addition: I think perhaps the author list inputted in the online fields may be used for citations but the paper itself will have me as first author. So perhaps my supervisor wants their name to be that cited?

I've completed a project in computational physics. 100% of the code and running of the code completed by me and the introduction, theory and code description in the paper written by me. Results section written by supervisor with some feedback from me.

When we put the latex together I was listed as first author on the paper, since, as my supervisor stated, I did 95% of the work. However, when the paper was submitted my supervisor listed themselves as first and corresponding author in the online submission fields (I was still first in the author list of the submitted paper - ie. in the actual latex document).

When I pointed this out to the supervisor they denied it, so I logged in to the journal account and sent a screen grab showing the status, They said that they must have made a mistake and would correct later when resubmitting (flagged for some missing documents).

Later on I got an email from my supervisor stating that they had submitted the documents but 'forgotten' to correct the author status but not to worry because I'm listed first in the submitted latex paper.

I'm not sure what to think here. Perhaps my supervisor is correct and it will make no difference (since I'm listed first in the latex paper) and is just winding me up. Either that or not I feel that I need to push back here, somehow without damaging the relationship.

Addition: I think perhaps the author list inputted in the online fields may be used for citations but the paper itself will have me as first author. So perhaps my supervisor wants their name to be that cited?