IMPORT TABLESPACE silently corrupts BLOB data

I have copied a .idb data file from an Debian 8 10.0.32 MariaDB to an Debian 9 10.1.26 MariaDB and imported the new tablespace with an identical `CREATE TABLE` statement.

The IMPORT went without problems, the table was accessible, but the BLOB data column was corrupted. Each BLOB data on the new DB had 3 (seemingly) random bytes at the beginning of the data and was missing 3 bytes at the end.

Importing the same .ibd file back to the original DB as well as to a different 10.0.32 MariaDB showed correct data.

`OPTIMIZE TABLE` on the new, imported table didn't fix the problem and didn't show any errors.

I can provide the `CREATE TABLE` statement and the DB file (~2GB, 240MB compressed) on request.