Q.Rose bush problem
Do you know what is causing this, on my rosebush leaves? The photo did not come through the first time, so I am trying again
I have 2 web articles that I hope will help you discover the problem. The first article discusses diseases and the second reviews rose problems in general. However, it specifically addresses browning leaf tips from salt damage. This isn't necessarily sea salt but the build up of fertilizer salts to toxic levels. A soil test will identify this problem.
https://www.gardeningknowhow.com/ornamental/flowers/roses/brown-edges-on-rose-leaves.htm
https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1528.pdf