WP Admin Side Throwing 404 Errors


Lately we have been having an intermittent problem with running into 404 errors when trying to navigate to certain pages on the back end of our wordpress site: https://cncmachines.net/. Most notably, they are the URL we use for logging in to the WP dashboard and when trying to view form submissions for the form plugin we are using called Gravity Forms. What makes things even stranger is that these 404 errors continue to appear for some of our admin users while working fine for other admin level users. I realize this isn't much info to go on but are there any general things I should be looking out for to debug this issue? Thank you for any help you can offer in this matter. Please let me know if I can provide any further detail if needed.