Filename error for TFTP recovery for a damaged embedded device

Question

I have a device that do not start, I connected it to my PC and launched Wireshark.

As you can see bellow, the device is asking for a file ends with semi-colon called recovery; to be uploaded through TFTP.

However, the recovery file I have for the device is recovery.dat.

I tried renaming the recovery file and uploading, uploading it as it is but did not work.

Any explanation possible to this?

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Trivial File Transfer Protocol
Opcode: Read Request
Source File: recovery;
       Type: octet
▸ Option: timeout = 5
Option: blksize = 1468