Hello,@ coffent

Follow this step,To Can't access a mapped drive

Step 1 :- Open Computer by clicking the Start button and then clicking Computer.
Step 2 :- Click Map Network Drive.
Step 3 :- In the Drive list, click any available drive letter.
Step 4 :- In the Folder box, type the path of the folder or computer, or click Browse to find the folder or computer.then Click Finish.

I hope this information will be usefull for you.
Thank You.