Having some problems with LTC4267

Hello, ADI Team

I am using the 5V non-isolated circuit provided in the datasheet to power my board,
but I had to change the transformer to Bourns 'POE060-FD20120S' due to supply issues during development.

Using the attached schematic, I fabricated several boards for testing,
and 20-30% of them exhibited issues with the PoE section.

The problematic boards were operated for several minutes, then the power supply stopped along with a noise sound,
and the MMBTA42 (Q1) transistor was found to be damaged.

There might be additional issues in other parts, but it is difficult to check them with the equipment I currently have.

I would like to know if there are any circuit modifications needed to accommodate the substituted transformer,
or if this transformer is simply not suitable for use with the LTC4267.

If this transformer is not suitable, I would appreciate it if you could recommend an alternative transformer that I could use.

Thank you for your time and assistance.