Stitch Together a Palindrome from Palindromic Substrings Given a string l, find all palindromic substrings p of l (including duplicates and single character strings). Next, rearrange all sub-strings in p into a valid palindrome (there may be multiple correct answers). If it is not possible to rearrange p into a single palindrome, your program may have undefined behavior (error, stack-overflow, exiting, hanging/untimely murder of John Dvorak, etc...)

Examples
Valid Test Cases
l = anaa
p = ['a', 'n', 'a', 'a', 'aa', 'ana']
result = anaaaaana or aanaaanaa or aaananaaa

l = 1213235
p = ['1', '2', '1', '3', '2', '3', '5', '121', '323']
result = 1213235323121

l = racecar
p = ['r', 'a', 'c', 'e', 'c', 'a', 'r', 'cec', 'aceca', 'racecar']
result = racecarcecaacecracecar (there are others)

l = 11233
p = ['1', '11', '1', '2', '3', '33', '3']
result = 113323311 or 331121133

l = abbccdd
p = ['a', 'b', 'bb', 'b', 'c', 'cc', 'c', 'd', 'dd', 'd']
result = bbccddaddccbb or ccbbddaddbbcc or (etc...)

l = a
p = ['a']
result = a

Invalid Test Cases (Not Possible)
l = 123456789
p = ['1', '2', '3', '4', '5', '6', '7', '8', '9']
result = &lt;not possible, behavior undefined&gt;

l = hjjkl
p = ['h', 'j', 'jj', 'j', 'k', 'l']
result = &lt;not possible, behavior undefined&gt;

l = xjmjj
p = ['x', 'j', 'jmj', 'm', 'j', 'jj', 'j']
result = &lt;not possible, behavior undefined&gt;


Rules

If the input word is a palindrome itself, it will always be valid as input.
Only one substring should be returned, which one you choose is arbitrary as long as it's valid.
If the input has no viable output, your code may have undefined behavior.
Inputs will only contain ASCII-Printable characters between 0x20-0x7E.
This is code-golf, lowest byte-count is the winner.
Brachylog, 10 bytes
{s.↔}ᶠpc.↔

Try it online!
Fails (i.e. prints false.) if not possible.
Explanation
{   }ᶠ         Find all…
 s.              …substrings of the input…
  .↔             …which are their own reverse
      p        Take a permutation of this list of palindromes
       c.      The output is the concatenation of this permutation
        .↔     The output is its own reverse