TSV stands for Tab Separated Values. TSV files are used for raw data and can be imported into and exported from spreadsheet software. TSV files are essentially text files, and the raw data can be viewed by text editors, though they are often used when moving raw data between spreadsheets
Unfortunately, I had a rather large TSV file recently that didn't play all that nicely with certain programs so I had to exert notable troubleshooting effort to try to figure out why the said programs didn't like it. It would have been nice if I could have just tried to import the TSV directly into Power BI without having to go through third party clients. There still may have been issues with the TSV but skipping the intermediate step may have saved me some notable time.
I made a tsv file from Excel (save as Text (tab delimited), then change extension to TSV), and was able to ingest that into Power BI. Maybe the file format is different than the files you are dealing with, but try to connect with CSV/TXT connector, and in the file picker change it to all file types. In the next screen, you can choose tab delimited and ingest the data. Alternatively, you can change the extension of your tsv to txt and use same connector.
Sorry if you've already tried that, but thought I'd chime in.