pg_restore unexpected end of file

I'm trying to migrate a database from version 11 to version 15.

I have created a dump file on v11:

pg_dump --dbname=not_telling -Fc --no-owner > dump

Then I was trying to import it on v15:

pg_restore -v --dbname=not_telling --no-user /restore/dump
pg_restore: error: could not read from input file: end of file

The file is 525MB. First I thought that maybe the dump is corrupt, so I
re-dumped the db again, but I got the same results. pg_dump does not report
any error, but pg_restore cannot import it.

I can try to export into SQL format, but there is another (much larger)
database that I need to migrate, and it has large binary blobs inside. I
would prefer the custom format.

Is the custom dump format of v11 compatible with v15?

Thank you,

Laszlo