Hi guest25648,
I understand your concern. As I mentioned to Abdullahhhhhh, it seems that the issue might be related to the firmware update on a Windows 11 system. Currently, Lenovo does not have Windows 11 drivers available for the IdeaPad S145-14API.
I would recommend checking if your machine originally came with Windows 11 or if you upgraded from Windows 10. If you upgraded, you might want to consider reverting back to Windows 10 until Lenovo releases compatible drivers for Windows 11.
We normally advise to update the BIOS firmware using the firmware version uploaded on the Lenovo support site. The BIOS normally controls how the fan behaves and how it throttles through the BIOS firmware version uploaded by the developers.
If the firmware update was prompted by the Lenovo Vantage app, you might want to check for any new updates or fixes there. You can download the Lenovo Vantage app from the Windows app Store.
If the issue persists, please consider reaching out to Lenovo's technical support for further assistance.
Best regards.
Dex_Lenovo