Yii2 Mariadb transaction commits fine, but nothing gets stored in DB - php

Question

I have a code:
$tx = Yii::$app->db->beginTransaction();
try {
// CODE (a lot of active-record reads and writes)
$tx->commit();
echo "All good!";
} catch (\Throwable $ex) {
$tx->rollback();
echo "Error";
}
It executes and I get "All good!" as a result.
However, nothing gets actually stored in database.
The code has been working for several months so far and wasn't modieid.
It suddently stopped working yesterday.
After an hour of debugging, I can confirm operations go fine, I can "echo" intermidate results, including IDs of the records I'm inserting. But still nothing saves in DB after the final commit.
If I remove transaction, the code works, and everything gets stored in DB, as it used to with Transaction around.
I want to ensure wholeness of the changes, want to get in back inside the transaction.
Or, at least, I want to understand which code (or DB state or whatever else) prevents data from being stored and why I don't get any exceptions and my "Error" echoed, since transaction failed to commit.
I was sure that if transaction fails to commit (actually write to DB), commit() method would throw an exception, but it does not. Is there a way to get it?
Thank you very much in advance.

Answer 1

The problem turned out to be in the code.
Thanks, #Michal Hynčica, you were right indeed.
There was a part like:
foreach (..) {
$tx = Yii->$app->db->beginTransaction();
if ($oneRareCondition) {
continue;
}
...
$tx->commit();
}
Was solved by adding $tx->commit(); before continue; in that rarely-happening if:
foreach (..) {
$tx = Yii->$app->db->beginTransaction();
if ($oneRareCondition) {
$tx->commit();
continue;
}
...
$tx->commit();
}