Weird problem with blocks.

[UNKNOWN.DESIGN.LAB]

Hey everyone, i am having a strange problem with blocks in a file. 

Minotti an italian furniture manufacturer is a brand that provides CAD blocks for some of their products. I download a chairs set cad block off their website and copy/paste it into this multi items file into my project model space and then i proceed download another multi item sofa block set off their website.

Upon copy/pasting the sofa block onto that working model file, the sofas pastes with block object(s) from the chairs file as well ! and sometimes substitutes items from one file with others from the other file. 

The blocks appear to share a field name or grouping category of some sort that causes the mixup.

Ex: The chairs file and the sofas file both share within their definition a field name or grouping labelled "Gruppo-15-1" by the manufacturer. Now these files contain several block and, say 10, they do not all share this same field or grouping name. Within the same file some will have the label "GRUPPO-15-1" others "GRUPPO-4-1" for example. Copy/pasting the blocks into a new drawing file works with no problem at all, while copy/pasting the same block into my working project file causes the problem to occur. 

Ill attach a screenshot with the grouping category or whatever that is for you guys to help me identify what that is and work to resolve the issue accordingly. 

I remember tampering with these categories somehow before attempting to learn more about blocks and since this problem has been happening. 

I am providing the example using Minotti's files but this does happen with other files from other sources as well so it is not a one off issue from their files and rather something in my project file that i messed up and am trying to fix. 

[maxim_k]

Hi,
The field you marked on your screenshot is not a grouping category - it is Block name of the block opened in Block editor.
Looks like drawings you downloaded have multiple blocks inside them with the same names inside each "category" drawing. So you need to rename blocks inside drawings you downloaded from site before inserting them into your project file.
Otherwise, you will always run into a block name conflict and - if the block with the name you are trying to insert from external drawing already exists in your target drawing, it's definition (contents) will remain as it is in target file.
Can you attach here one of the drawings with blocks you downloaded from Minotti site?

[UNKNOWN.DESIGN.LAB]

@maxim_k  They do have multiple block inside that is true. How can i rename blocks inside the drawings ? your on to something 

[maxim_k]

Open drawing with multiple blocks, then use RENAME command:

http://help.autodesk.com/view/ACDMAC/2019/ENU/?guid=GUID-99C5072C-C71E-4BF7-9B3B-69B3BEA07940

to rename blocks inside that drawing.
You can use, for example, prefix with the name of the drawing with multiple blocks.