Confusion with Portugal's immigration, affecting new visa application?

Based on the information you provided, your overstay appears to have resulted from misinformation and difficulties securing an appointment with AIMA, compounded by a reasonable belief that your visa was extended. While overstaying is a serious issue, authorities may take into account the systemic barriers and your lack of intent to violate the rules. Regardless, this overstay can be fined, but these fines are usually not applied. However, we can't guarantee that this will happen given that, as mentioned before, the authorities may impose a fine for your overstay. In your new visa application, providing a clear and detailed explanation of your situation is crucial, supported by evidence. This includes documentation of your attempts to secure an appointment, such as emails or call logs, any official communications regarding visa extensions during the period in question, your full-time employment contract in Portugal demonstrating your ties and commitment to the country, and a timeline outlining the efforts you made to comply ith regulations and any barriers you encountered. In your cover letter to VFS, you should emphasize that your overstay was unintentional and explain the sequence of events that led to it. Express your commitment to resolving the situation promptly and complying with all future immigration requirements. While providing a strong explanation and evidence can increase your chances of a positive outcome, there is no guarantee of success. Immigration authorities may scrutinize your case carefully, but demonstrating good faith and a genuine attempt to comply with the rules should work in your favor.