Filter.duplicate and filter.distance used with Watch protocol interpretation

When i use these settings in traccar.xml

    <entry key='filter.enable'>true</entry>
    <entry key='filter.duplicate'>true</entry>
    <entry key='filter.invalid'>true</entry>
    
    <entry key='filter.accuracy'>100</entry>
    <entry key='filter.skipAttributes.enable'>true</entry>
    <entry key='filter.skipAttributes'>alarm,event,result,status</entry>
    <entry key='filter.skipAlarm'>true</entry>

Then i see that Filter.duplicate also filters Link keep messages.

2021-03-06 01:39:41  INFO: [ae8313de: watch < 83.232.61.114] HEX: 5b33472a323530333239383835372a303030392a4c4b2c302c302c39375d
2021-03-06 01:39:41  INFO: [ae8313de: watch > 83.232.61.114] HEX: 5b33472a323530333239383835372a303030322a4c4b5d
2021-03-06 01:39:41  INFO: Position filtered by Duplicate filters from device: 2503298857

From HEX

[3G*2503298857*0009*LK,0,0,97]
[3G*2503298857*0002*LK]

2021-03-06 01:39:50  INFO: [c6177cb9: watch < 89.200.44.98] HEX: 5b33472a303330343037303738312a303030412a4c4b2c302c302c3130305d
2021-03-06 01:39:50  INFO: [c6177cb9: watch > 89.200.44.98] HEX: 5b33472a303330343037303738312a303030322a4c4b5d
2021-03-06 01:39:50  INFO: Position filtered by Duplicate filters from device: 0304070781


2021-03-06 01:40:16  INFO: [44890e53: watch < 185.226.110.114] HEX: 5b33472a323530333838353436352a303030412a4c4b2c302c302c3130305d
2021-03-06 01:40:16  INFO: [44890e53: watch > 185.226.110.114] HEX: 5b33472a323530333838353436352a303030322a4c4b5d
2021-03-06 01:40:16  INFO: Position filtered by Duplicate filters from device: 2503885465

Also see this from Filter.distance in tracker-server.log (before i removed it from the config)

2021-03-05 16:28:21  INFO: [cc84112d: watch < 62.133.103.234] HEX: 5b33472a303330343037303738312a303030392a4c4b2c302c302c35305d
2021-03-05 16:28:21  INFO: [cc84112d: watch > 62.133.103.234] HEX: 5b33472a303330343037303738312a303030322a4c4b5d
2021-03-05 16:28:21  INFO: Position filtered by Distance filters from device: 0304070781

From HEX

[3G*0304070781*0009*LK,0,0,50]
[3G*0304070781*0002*LK] 

Devices stay online though.

Is this correct ? I wonder why this happens, and how it can be solved.

Looks correct.