incorrect detection of missing comment

[KristofSzabados]

When running the latest PMD plugin on our code we get a violation report we believe to be false positive.
PMD plugin version used is: 4.18.0.v20201024-1129
Containing PMD version: 6.29.0

The project used is open source: https://github.com/eclipse/titan.EclipsePlug-ins
The file where we get the report is: https://github.com/eclipse/titan.EclipsePlug-ins/blob/master/org.eclipse.titan.runtime/src/org/eclipse/titan/runtime/core/TitanLoggerApi.java
in line : 1382
violation report: "CommentRequired: Public method and constructor comments are required"

The code in question looks like this:
"
/**
* Gives access to the field id.
* Turning the template into a specific value template if needed.
*
* @return the field id.
* */
public TitanInteger_template get_field_id() {
set_specific();
return id;
}
"
As it can be seen while the function is truly public ... it also visibly has a comment.
What makes this issue more interesting is that this does not look like a consistent problem.
The public function directly following this one (with very similar signature and comment shape/form/content) does not have this violation reported on it.
I have attached 2 images showing both functions together and the reported violation.

Please note this happens several times in the code ... this occurrence was just the smallest I could find to demonstrate the issue.

Please also note, that this file is generated and so quite large (>160K lines).
This might play a role in creating the issue.