It appears that the name of days are not correct on the arabic calendar, but once the selection is done, the right day is selected. This is a screenshot from today (1st of August). It says Wednesday above the 1st of August but when selected Tuesday appears in the answer box.
Survey123 2.3.29, Connect 2.3.24
Can you please confirm if you are still seeing this issue in 3.1?
If so please confirm the exact language and locale settings you have applied on the device/survey, and the device/platform you are using.