Recipients addresses not formatted correctly when entered via Gboard contact suggestion

Hello, this issue may be linked to #3577 and looks similar to #1495 (which is closed)

Expected behavior

1. I start typing a contact name as recipient for my message, say "will"
2. Gboard offers a corresponding suggestion from my address book
3. I select the one I intended: "william@blabla.com"
4. The address selected should be inserted as usual in the recipients field
5. Then I start typing the name of the next recipient, say "geo", and again selects the Gboard suggestion of "georges@blabla.com"
6. This last address should be added to the recipients field

Actual behavior

From Step 4: the address entered in the recipients field is not visually changed to the form they take usually, until I also select the same address from K9 suggestion of "William" from my address book
Step 5: If I start typing the next address without selecting the suggestion from K9, then the first address will not have been "converted" to whatever it seems it should have been: its visual aspect remains as simple text, and the two addresses are only separated by a space
Result: I end up with an address analysis error warning

Steps to reproduce

1. activate Gboard autocorrect setting "suggest addressbook contacts"
2. create a new message, start entering a name from your address book
3. do not select the contact suggested by k9 in the popup
4. select the suggestion from Gboard
5. start typing the next name from your address book and select the suggestion from Gboard again
6. your recipient field presents an address analysis error warning

Environment

K-9 Mail version: 5.403

Android version: same behavior on both

Android 7.0 on Archos Phone
Android 5.0 on Asus Tablet
Account type (IMAP, POP3, WebDAV/Exchange): I can see no link with this but I have multiple IMAP accounts

Start by reproducing the issue in K-9 Mail 5.403 with Gboard contact suggestions enabled, following the listed recipient-entry steps. Then trace the recipient field's handling of successive Gboard-selected addresses; done means multiple selected addresses are formatted and separated normally without an address analysis error.