Arrangement marker issue

You will notice on the screen shot below, that i have a project that uses both Arrangement Markers and ordinary markers. My question focusses on the top line or markers (the Arrangement Markers)

If you look at the Arrangement marker entitled Chorus 2B (highlighted in pink), you will notice that right beside it, there is a Bridge (colored Blue) .

When you look at the ruler, you will notice that the Bridge starts at 57.

I am trying to get the bridge to start a littler bit earlier. I'd like it to actually at 53. This means that the section marked Chorus 2b, has to end earlier at 53.

I thought I could easily drag the left side of the bridge marker, over to 53, and the bridge would start earlier as described above. But it does not seem to be doing that. I thought by dragging the he left side of the bridge marker over to 53, the music below the bridge marker and further to the end of the song, would also move over to 53.

What am i doing wrong? My goal is simply to get the bridge to start a little earlier and the Chorus2b to end a little earlier.

Thank-you for your time and expertise!