Monthly Last Days (-1, -2, -3, -4) Highlight issue

[viveksudani]

When I load model page to edit, schedule (recurrence field), Monthly Last Days like -1, -2, -3, -4 options are not being highlighted, even if it is selected. (Image Below)

Example
-- I select monthly last, second last and save the item. (RRULE:FREQ=MONTHLY;BYMONTHDAY=-2,-1)
-- When I reopen the model item to edit recurrence field, It doesn't highlight the -1, and -2 cells. (Image Below)

-- Then, If I select the -3, the -1 and -2 (previously selected options) are getting cleared from displayed text. (Image Below)

Hope I explained this well!
Thanks