Hello,

You set it as a one-way street but you provided no exemption tag for cyclists.

Most streets have M2 or M3 signs granting access contraflow.  It is very likely there would be one here.
(https://wiki.openstreetmap.org/wiki/File:Belgium-trafficsign-m2.svg)

On top of "oneway=yes" which you added, we must add "oneway:bicycle=no" to reflect this.

Can you please tell us whether you spotted such a sign?  Ideally, did it include just bicycles, or moped A and/or moped P?  Thanks in advance.