Well, maybe “ragged” is a bit a dramatic of a description of me. But the bold font appears thinner than it should be, especially at the bottom edge of characters. As if you have zoomed out a bit.
If I use the Chrome Developer Tools to replace the “600” values in the font declaration with “700” (= “bold”), than the font appears full & clearly legible (again), as it should be.
See this screenshot: https://durfteimproviseren.nl/wp-content/uploads/fonts%20rendering.jpg The upper part of the screenshot is the current situation, the lower part is how it should be.