A student temporarily present in the United States under an “F,”“J,”“M,” or “Q” visa, who substantially complies with the requirements of the visa may be treated as “exempt individual” - means - you do not count days for which you are an exempt individual for the substantial presence test in determination if you are a resident alien or a nonresident alien.
If you exclude days of presence in the United States because you were temporarily in the United States as a student, you must file a fully completed Form 8843.
Generally - you should attach Form 8843 to your income tax
return. If you do not have to file a return, send Form 8843 to the Department of the Treasury, Internal Revenue Service
Center, Austin, TX 73301-0215.
If you meet the substantial presence test and do not file form 8843 - you are treated as a resident alien and exemption from FICA mentioned above would not apply for your situation. That is in relation to you question - "How come my F1 status came into play"
Sorry if the tax law
doesn't favor your situation.
Please do not shoot the messenger - I may only explain the law - but may not change it.
Please feel free to ask if any clarification needed or if you have other tax related issues.