Ok waiting for the solutions.
The below info maybe the guide to you for strange characters issue.
I’ve purchased Woocommerce Countdown Timer plugin last week then it was appearing in the single product page but not in the categories view above in the add to cart button. I contacted with the author of the plugin then he resolved the issue but in the other hand, he resolved the strange characters problem too. Its not the plugin i know but maybe the countdown timer not showing problem and strange characters problem has the same origin.?
On mobile, strange character problem was appearing from the beginning.
Keep in mind.