Bug with bookmarks

Hello! I think I found a bug with deleting bookmarks. Let's say this is my plain text document:

This is sentence 1.
This is sentence 2.
This is sentence 3.
This is sentence 4.
This is sentence 5.

So I create B1 and B2 bookmarks for sentence 1 and 2 (S1 and S2 for short). I delete B2 bookmark. Then I add a new B3 bookmark for S3.
 
Now I have two bookmarks: B1 and B3. But B3 doesn't work. When I select it, the app doesn't jump to that sentence.
I add two more bookmarks, B4 for S4 and B5 for S5. So now I have 4 active bookmarks and this is their behaviour:

B1 - jumps to S1 ✅
[B2 - deleted bookmark] 👻
B3 - does nothing ❌
B4 - jumps to S3 ❌
B5 - jumps to S4 ❌

It seems that deleting a bookmark corrupts the indexing somehow?
 
If I restore the deleted bookmark(s), everything works fine:

B1 - jumps to S1 ✅
B2 - jumps to S2 ✅
B3 - jumps to S3 ✅
B4 - jumps to S4 ✅
B5 - jumps to S5 ✅

@Voice Aloud Reader version: 25.2.7
@Voice Sync Plugin version: 4.0.4
@Voice License version: 1.7.4
Android version: 11