install shows ok. browser shows 8.1.8. terminal shows 8.0.21. no matter how many times I restart terminal, or relink php.

php info loads ok, but every other php has errors. drupal 9 kind of runs but update or install errors.
other php error even though code checkers show valid for 8.1.
nothing really helpful in logs.

any ideas how to fix? only updating php because new version of drupal requires it and I cannot seem to get the new php to work properly.