K9 Android - Cannot properly parse comma-separated email addresses when pasting list of addresses to TO and/or CC fields.

Expected behavior

Copying a list of comma-separated email addresses from any plaintext editor into the TO and/or CC fields if K9 in Android should result in a properly displayed and parsed list of email addresses like every other normal email client application.

Actual behavior

K9 under Android totally mangles the list except for either the first or last email address. Mangled results range from extra . inserted or , not recognized or a +1 string added BETWEEN email addresses or a K9 error popup with a red exclamation mark stating "Error parsing address".

Steps to reproduce

1.create a list of email addresses you want to send your email to inside a plaintext editor UNDER ANDROID.
For example: email1@test.com, email2@screwedup.com, testing@me.com, screwk9@kshit.com

2.copy and paste the above list into any TO or CC field in K9 under Android.

3. Tap any other field to leave to TO or CC field you pasted the email list to.

4. Watch K9 add a +1 between the first and remaining email addresses. Then when you tap on the TO or CC field to try to fix the mangling, K9 mangles it further and in some cases a red exclamation mark comes up saying Error Parsing Address.

Environment

K-9 Mail version: 5.208
Android version: 7.1.1
Account type (IMAP, POP3, WebDAV/Exchange): POP3

Start by reproducing the issue in the Android TO and CC fields using the comma-separated addresses from the report, then inspect the address parsing and recipient-field entry points. Done means pasted comma-separated addresses are displayed and parsed as separate recipients without mangling or an “Error parsing address” message.