When building websites, I once focused on a tiny difference: does a page address end with a slash? Sometimes both versions showed the same content. I wrote that this automatically meant lost link value and serious SEO trouble. That was too strong.
Choose one recognizable address
When two addresses lead to the same page, reports and shared links can become confusing. Decide which URL you want to publish and use it consistently in internal links. The presence of a slash matters less than consistency. Check what happens when somebody opens the alternative.
If you do not need the other URL, a permanent redirect can send visitors to the preferred version. In other cases a canonical annotation may help. Google describes redirects and rel=canonical as signals for the preferred URL. Google can also group similar pages itself; duplicate addresses do not automatically mean a penalty.
Check your own site
My old examples from other companies say little about how their sites work now. Instead, inspect a few of your own pages, internal links and sitemap. If a migration left old addresses behind, record where they should lead. The goal is a predictable route for visitors and a clear main version for search engines, not an absolute preference for or against the slash.