themes – Mobile Menu drop down goes blank help me fix it

Digiqole Theme menu on Mobile goes white.
The theme is great but when you try accessing the website from your mobile, you will notice that (the theme mobile menu background and the text it self goes white) I tried using the customise button but did not work. This my website

Have also contacted the theme developers but till date no response.
So I was hoping if anyone could help with this or if with any css
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