Japanese column names in SharePoint lists

Question

I'm using Graph to create columns in a SharePoint list. One column has a Japanese display name and another is a calculated column where the formula is just "=部署" ie a simple reference to the first column (this is a contrived example, my actual formula requirement is more complex).

I find that certain combinations of Japanese characters (always the same in the first column display name and second column formula) work but others cause a throw of error "The formula refers to a column that does not exist". In general non-Unicode characters seem fine and one Chinese character combination was okay but I've found that error (so far) only with some Japanese characters.

For instance, the name "部署" (the first two characters of "Title") fail but "部署部署" (the same two repeated) succeed. "部署住所１" (address 1) fails but "部署住所" removing the 1 succeeds.

Is this a known issue, is there a work-around or fix in the pipeline?