The Reversed Comma (⹁) (U+2E41) shows as a blank square, even though some other comma types such as the Arabic one works fine

This type of comma is used a lot in the Malay Jawi translations in the place of the regular Arabic Comma, as Jawi has it's own sets of punctuation marks that is slightly different than in Arabic...

Example #1 - Comparison with other comma types

Reversed Comma compared with the Regular Comma (U+002C) and the Arabic Comma (U+060C). The Arabic Comma seems to be rendered with the Unicode font even without Force Unicode Font enabled.

Example #2 - "Two Birds One Arrow" advancement

The Jawi Malay translation for the Two Birds One Arrow advancement (دوا بوروڠ⹁ ساتو انق ڤانه) uses the reversed comma... This is the easiest example I could give

Steps to Reproduce
Example #1
1. Copy and paste the following command, then execute it:

/tellraw @s [{"text":"minecraft:default: , ،  ⹁\n","font":"minecraft:default"},{"text":"minecraft:uniform: , ،  ⹁","font":"minecraft:uniform"}] 

    The comma shows as a blank box while the other two works fine when using the Unicode font

Example #2
1. Change the language to Jawi Malay, located at the very bottom of the language page
2a. Copy and paste the following command, then execute it;

/tellraw @s [{"translate":"advancements.adventure.two_birds_one_arrow.title","font":"minecraft:default"},{"text":"\n"},{"translate":"advancements.adventure.two_birds_one_arrow.title","font":"minecraft:uniform"}]

2b. Or grant the Two Bird One Arrow using the following command once each with and without Force Unicode Font enabled:

/advancement grant @a only minecraft:adventure/two_birds_one_arrow

    The comma shows as a blank box when using the unicode font