Can't send long text: Android warning and error code 5

[Cwpute]

Checklist

• I can reproduce the bug with the latest version given here.
• I made sure that there are no existing issues - open or closed - to which I could contribute my information.
• I made sure that there are no existing discussions - open or closed - to which I could contribute my information.
• I have read the FAQs inside the app (Menu -> About -> FAQs) and my problem isn't listed.
• I have taken the time to fill in all the required details. I understand that the bug report will be dismissed otherwise.
• This issue contains only one bug.
• I have read and understood the contribution guidelines.

Affected app version

1.0.1

Affected Android/Custom ROM version

Android 11

Affected device model

Nokia TA-1157

How did you install the app?

F-Droid / IzzyOnDroid

Steps to reproduce the bug

1. To a single contact, send a message comprised of 3263 characters
2. Android shows the same 5 warning about the app sending too much SMS (probably for the 5 SMS this message is made of)
3. The app gives 5 error messages: Unable to send message, code error: 5.
4. Let all toast messages disapear, and hit Authorize on each of the system's warnings
5. The message is not sent despite being marked as such below the message bubble

Expected behavior

If the checkmark is shown below the long message, then the message should be sent as expected.
The app shouldn't trigger Android's warning so much. Maybe once, so the user is warned, but not so in consecutive hits like that.
The app shouldn't show 5 toast messages with the same error code. The first one is sufficient.
If the message has not been sent, provide the user with a quick way to send it again, or fix the issue.

Actual behavior

I just tried to send a message only comprised of text, but it wouldn't send.
The message is 3263 characters long, and is encoded into 3341 bytes.
I got no less than 5 different messages from Android warning me the app was trying to send too many SMS. I also got 5 different toast messages warning the message could be sent: Unable to send message, code error: 5.

Screenshots/Screen recordings

In the screenshot below: both the app's toast message and Android's warning showing on top of the long message i was trying to send.

Additional information

tried to report it already in issue #213 but the form didn't show up on my github app.

[Aga-C]

Do you have enabled Send long messages as MMS in Settings?

[Cwpute]

No i haven't.
I just activated it and sent the same message again to see if it changed anything. It did, the long message went through.