Micropython on BW16. Load .mpy modules

I have installed the latest version of the ameba micropython port on a BW16 board.
(MicroPython v1.1.0-ameba on 2022-12-19; Realtek Ameba with BW16)
When ever I try to import a .mpy module with mpy version 6 the board freezes. Mpy version 6 is required any other version rejected (which is normal behaviour)
sys.implementation shows
(name=‘micropython’, version=(1, 18, 0), mpy=7174)
which is strange because mpy=7174 resolves to
mpy version: 6
mpy sub-version: 0
mpy flags: -march=armv7emsp

but micropython version 1.18.0 uses mpy version 5 not 6!

Therefore I build a mpy module for mpy version 5 and changed the version in der header to 6.0. The module was excepted but failed to load (name too long exception) At least it did not freeze the board.

How can I import / load .mpy modules with the ameba port, is it enabled?