Separated by the Meridian polygons in geomaps SAS VA (SAS GRAPH)

I'm trying create custom maps to Russia in Visual Analytics. So, I've faced with a trouble of "separated region".
You can see a visualization of this problem by using Dal'nevostochnyy (DVFO) region from MAPSGFK library.

I tried to fix the scatter by this code:

data mps.vaasia1;
set mps.vaasia1;
if LONG < 0 and isoalpha2="RU" then long=long+360 ; 
run;

And so I get this result (on picture imaged region Chukotka, but it dosen't matter):

It's better then previous situation, but it's look like crutch.
I've try to combine this two polygons by using GREMOVE (also add paramether FUZZ), but result was as the same.

UPD:
I use this code to get coordinates:

data ch;
set mapsgfk.Russia;
where id ="RU-77" ;
if LONG LE 0 then  long=long+360 ; 
x=long ;
y = lat;
run;

So my question is:
How can I delete space between two separated regions?

Thx for your answers / comments.

Thanks @Jor for you post. Your answer pushed me to thought: "May be I can't merge two poligons because they don't have common points?". So, I saw task like this:

1. Remove points between polygons (Red squares in picture below)
2. Set edge's polygons dots coordinates equal (Blue arrows)

data ch
/*Drop out dots with coord in red squares*/
(where=(not(lat > 66 and lat <68 and long >179 and long<181) ));
set mapsgfk.Russia;
where id ="RU-77" ;

if LONG LE 0 then  long=long+360 ; 

/*Set coordinates of near edge's points the same*/
if (long > 179.9 and long < 180.3) then do; 
    long =180;
    if (lat > 68.9 and lat < 69) then lat=68.97;
    if (lat > 65 and lat < 65.1) then lat=65;
    if (lat > 70.9 and lat < 71) then lat=70.95;
    if (lat > 71.5 and lat < 71.6) then lat=71.55;
end;

x=long ;
y = lat;
run;

proc gremove data=ch out=ch;
by id;
id id1;
run;


proc gmap data=ch map=ch;
id id;
choro id/nolegend;
run;
quit;

Result: