I'm not entirely sure how reliable this data is or what they mean exactly but Greece has had a mixed history with Albania. Albanians are more or less fully interweaved in the fabric of greek society at this point, both historically but also in more recent times.

When Albania collapsed thousands upon thousands of Albanians flooded Greece. Many people didn't like this and considered it an "invasion", but the fact of the matter is that Albanians filled many much needed labor positions that greeks were either unwilling to do themselves or unwilling to pay better money for so that greeks would bother with them. Albanians literally built modern day Greece as they were mainly occupied in farmwork and construction during Greece's bubble years. They worked hard and nowadays most of them enjoy a much better life than the one they had in Albania, with many of them being business owners nowadays.

Obviously this wasn't that well received by everyone. While many benefitted greatly by cheap Albanian labor, working class people considered Albanians to be unfair competition in the job market, devaluing the labor value of certain jobs and "stealing" jobs from locals. Of course the reality of the situation is not much different from what's happening today with imported immigrant labor from other places. Employers actively seek out illegal immigrants to exploit for low pay, and locals either don't want to do these jobs or they won't due to the low pay. The immigrant is not really the one at fault but working class people will turn against them instead of turning against the real culprits.

We also can't ignore the fact that along with economic migrants, the Albanian mafia also intruded the country. A lot of albanians were involved in crime, from petty theft or low volume drug sales up to full blown mafia operations. This left a stain on their reputation with some older people still considering that all Albanians are criminals. This isn't true but immigrants always have an uphill battle when it comes to being accepted into a new country and any negative thing is amplified easily.

While Albanians are finally enjoying a good level of acceptance in greek society, older prejudiced notions still remain, and I think that some people consider the acceptance of Albania into the EU as a second "wave" of Albanian invasion like the one in the 90s. And of course the government benefits from this idea because as long as people think that other people are their problem they won't focus on the fact that it's always been their own government failing them and not doing right by them instead of immigrants disrupting their communities.