Multilingual mode prevents adding new price sets
If you enable multilingual mode, additional columns are added to the civicrm_price_set table and other columns are re-named (e.g. title_lang_LOCALE and title_lang_LOCALE). This is not respected by the code that creates new price sets, which does not add values for those columns. The code also attempts to add a row to table
civicrm_price_set_lang_LOCALE, which does not exist (it is civicrm_price_set with some columns changed).
Not sure how any of this works, so not going to try to fix it myself, so just reporting here. 5.38.alpha1
EDIT: Can't duplicate on dmaster, closing.