I actually could not find the law. I’m a bit confused because Belgium supposedly has an exceptional open data law. But at the same time there is an EU Directive (2019/1024) which requires all member states to have an open data law. I cannot find Belgium’s implementation of this law. But in any case, Germany should have implemented the directive to ensure the data is machine readable:

Article 14
Specific high-value datasets and arrangements for publication and re-use
1.
The Commission shall adopt implementing acts laying down a list of specific high-value datasets belonging to the
categories set out in Annex I and held by public sector bodies and public undertakings among the documents to which
this Directive applies.
Such specific high-value datasets shall be:
(a) available free of charge, subject to paragraphs 3, 4 and 5;
(b) machine readable;
(c) provided via APIs; and
(d) provided as a bulk download, where relevant.
Those implementing acts may specify the arrangements for the publication and re-use of high-value datasets. Such
arrangements shall be compatible with open standard licences.
The arrangements may include terms applicable to re-use, formats of data and metadata and technical arrangements for
dissemination. Investments made by the Member States in open data approaches, such as investments into the
development and roll-out of certain standards, shall be taken into account and balanced against the potential benefits
from inclusion in the list.
Those implementing acts shall be adopted in accordance with the examination procedure referred to in Article 16(2).
The Commission shall adopt implementing acts laying down a list of specific high-value datasets belonging to the
categories set out in Annex I and held by public sector bodies and public undertakings among the documents to which
this Directive applies.
Such specific high-value datasets shall be:
(a) available free of charge, subject to paragraphs 3, 4 and 5;
(b) machine readable;
(c) provided via APIs; and
(d) provided as a bulk download, where relevant.
Those implementing acts may specify the arrangements for the publication and re-use of high-value datasets. Such
arrangements shall be compatible with open standard licences.
The arrangements may include terms applicable to re-use, formats of data and metadata and technical arrangements for
dissemination. Investments made by the Member States in open data approaches, such as investments into the
development and roll-out of certain standards, shall be taken into account and balanced against the potential benefits
from inclusion in the list.
Those implementing acts shall be adopted in accordance with the examination procedure referred to in Article 16(2).

(shitty paste but readable enough)