tofu in fill in the blanks

I am no expert, but the AI failed me in fixing the following problem. Can anyone help me? Thanks!

1. In moodle 5.01, our fill in the blank activities used to be displayed fine, but after some updates in the summer, we no longer see fill in the blanks correctly. The buttons (like check) are displayed as tofu and the input boxes have vanished. The text is displayed normally and you can actually use it by clicking on the non existing blanks and the tofu-buttons. But it looks so bad that kids won't be able to use it.
2. Desktop
3. all browsers
4. H5P-Framework v1.27 (h5plib_v127), fill in the blanks 1.14.37