You have only 2.8GB of storage left on the APIM, as the EU maps did not overwrite the NA maps, nor will they. Since you have a MY20 vehicle, reformatting is not an option. Normally placing a cut down version of EU maps will work, with voice, etc., but since this is a MY20 APIM (5U5T-14G371-CKC) this my not be possible. You can see below that there are 10 map files installed, 1 NAV Voice file, and the small -EM system voice file. The region is set to 504C, Poland.
If you have not done so, perform a Master Reset and then try to install the 5U5T-14G391-AN_1615393794000.TAR.GZ package again. There is enough storage on the unit for this file to decompress and install, it requires 1.9GB. You will not be able to install Gracenotes.
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.4G" available="12M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.4G" available="36K"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.4G" available="148K"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.3G" available="12M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="922M" available="3.0M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.3G" available="9.3M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.7G" available="16M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="1.1G" available="892K"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="3.2G" available="5.7M"/>
<d2p1:PartitionHealth type="/fs/sd/MAP/" total="3.1G" available="24M"/>
<d2p1:PartitionHealth type="/fs/Nuance/" total="3.6G" available="35M"/>
<d2p1:PartitionHealth type="/fs/Nuance/" total="244M" available="940K"/>
<d2p1:PartitionHealth type="/fs/rwdata/" total="1.2G" available="645M"/>
<d2p1:PartitionHealth type="/fs/rwdata/quip/" total="35M" available="34M"/>
<d2p1:PartitionHealth type="/fs/rwdata/quip/" total="90M" available="85M"/>
<d2p1:PartitionHealth type="/fs/mp/" total="1.4G" available="133M"/>
<d2p1:PartitionHealth type="/fs/images/" total="25G" available="2.8G"/>