When you see a PIN to a certain extent, the PIN code in the window remains unchanged and the Progress percentage does not go, congratulations! You have encountered an endless loop.
1. Keep the original window unchanged, open a shell, and then execute
Reaver-I mon0-B is PIN MAC-a-s-vv
2. pin to 90.9% infinite loop, indicating that the first four digits have been pin, but no result is returned, probably because the AP did not send a confirmation message, reaver has skipped, thus missing the confirmation of the correct first four digits.
The endless loop from pin to 99.9% indicates that the first three of the last four digits have been completed, but none have been generated. The reason is the same as above.
Most people execute commands with the suffix-vv-a-S after MAC. However, although such suffixes can speed up, you may also miss the confirmation of the correct first four digits. Therefore, the expression for every confirmation message is
Reaver-I mon0-B MAC-v-a-n
You don't need anything else. You can also add a-c