In /subsystem=messaging-activemq/server=default is described attribute:

 "transaction-timeout" => {
                "type" => LONG,
                "description" => "How long (in ms) before a transaction can be removed from the resource manager after create time.",

which is misleading. Based on code review if Artemis transaction is part of XA transaction or one-phase but still under coordination of Transaction Manager then this timeout is changed by Transaction Manager to timeout defined in transaction subsystem:

[standalone@localhost:9990 subsystem=transactions] :read-resource
{
    "outcome" => "success",
    "result" => {
        "default-timeout" => 300,

We should provide this information to description of transaction-timeout attribute in messaging-activemq subsystem.