Bash 4.2 / 4.3: different behavior in a C-style loop

bash

4.2 shows the intended correct behavior in a C loop:

me@server:/some/dir# TIMES=30; for (( n=0; n<$(shuf -i ${TIMES}-$(expr ${TIMES} + 20) -n 1); n++ )); do echo $n; done
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me@server:/some/dir# bash --version
GNU bash, Version 4.2.25(1)-release (x86_64-pc-linux-gnu)
(...)
me@server:/some/dir#

      

        
        
        
      

    

Same in bash

4.3 throws an error:

me@server:/some/dir# TIMES=30; for (( n=0; n<$(shuf -i ${TIMES}-$(expr ${TIMES} + 20) -n 1); n++ )); do echo $n; done
-bash: syntax error near unexpected token `newline'
me@server:/some/dir# bash --version
GNU bash, Version 4.3.30(1)-release (x86_64-pc-linux-gnu)
(...)

      

        
        
        
      

    

However, part of finding a random number between ${TIMES}

and ${TIMES}+20

works:

me@server:/some/dir# shuf -i 20-50 -n 1
26
me@server:/some/dir#

      

        
        
        
      

    

It also inserts a digit directly instead of $()

-subshell'ing:

me@server:/some/dir# TIMES=30; for (( n=0; n<26; n++ )); do echo $n; done
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me@server:/some/dir#

      

        
        
        
      

    

What's going on here? Any ideas why the subshell is not executing correctly in bash

4.3?