Hello,
why doesn't mapsforge map mtk_suomi.map from https://kartat.hylly.org/ load properly?
mtk_suomi.img works fine
It's the same problem with 7.4.26 (apk version) and the latest Google Play version.
See the screenshots.
Putting https://kartat-dl.hylly.org/2023-03-18/peruskartta.zip to mapstyles folder and then selecting the Peruskartta mapsforge theme in the left upper corner menu fixes the problem.