Failure to approve acme cert

I have a domain and manage it through route53. I use ACME for several other servers. When I try to approve a CSR using ACME in freenas I get the following response:

Error: Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/middlewared/job.py", line 349, in run
await self.future
File "/usr/local/lib/python3.7/site-packages/middlewared/job.py", line 385, in __run_body
rv = await self.method(*([self] + args))
File "/usr/local/lib/python3.7/site-packages/middlewared/schema.py", line 961, in nf
return await f(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/crypto.py", line 1279, in do_create
job, data
File "/usr/local/lib/python3.7/site-packages/middlewared/utils/run_in_thread.py", line 10, in run_in_thread
return await self.loop.run_in_executor(self.run_in_thread_executor, functools.partial(method, *args, **kwargs))
File "/usr/local/lib/python3.7/site-packages/middlewared/utils/io_thread_pool_executor.py", line 25, in run
result = self.fn(*self.args, **self.kwargs)
File "/usr/local/lib/python3.7/site-packages/middlewared/schema.py", line 965, in nf
return f(*args, **kwargs)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/crypto.py", line 1325, in __create_acme_certificate
final_order = self.acme_issue_certificate(job, 25, data, csr_data)
File "/usr/local/lib/python3.7/site-packages/middlewared/plugins/crypto.py", line 956, in acme_issue_certificate
normalised_san = ':'.join(self.middleware.call_sync('cryptokey.normalize_san', [domain]))
TypeError: sequence item 0: expected str instance, list found