GDocs extension: missing highlight when first char is ?

[snomos]

Input text:

– Mun háliidan doarjut Bonju Sápmelaččaid ja illudin searvat ráidovázzimii singuin lávvardaga, cealká gielda- ja ođasmahttinministtar Jan Tore Sanner,gii ovddasvástida ovddasvástida sámi áššiid ráđđehusas.Europride-festivála loahpahuvvui ráidovázzimiin Oslo gáhtain mannan lávvardaga?Bonju Sápmelaččat vázze sierra joavkun dán ráidovázzimis!Lassin dasa lei vel Queering Sápmi-čájálmas Pride Parkas Ráđđeviesu šiljus.

1. run the grammar checker (North Sámi)
2. you should get five errors (see screen shot below)
3. notice how the third error and suggestion (?Bonju ⇒ ? Bonju) does not trigger a highlight when the mouse is moved over the error message. Instead the previously highlighted word is kept highlighted.

This only happens in GDocs, MS Word behaves just fine. The only trigger I can think of is the initial ? character in the highlighted text.