More than 2.5 million Ukrainians have returned to their country since Russia invaded, border police have said.
EU border agency Frontex said more people were heading into Ukraine than out at the moment.
The number of refugees arriving in Poland has slowed to about 145,000 over the past week, almost as many as were crossing every day at the height of the evacuation in March.
By contrast, 163,000 Ukrainians went back over the several land crossings from Poland and entered their home country in the first week of June.
People returning to Ukraine are not necessarily staying for good. UN officials have described people going back and forth for various reasons, including visiting families, checking their properties and helping others to escape.
The total number of crossings from Ukraine passed seven million this week, although that could include several arrivals by the same people. About 3.8 million of those crossings were at the Polish border.
EU countries eased immigration rules in March to grant Ukrainians automatic one-year residency in the bloc, but some have said they would rather go home as the war drags on past the 100-day mark.
Despite the slowdown in departures from Ukraine, pressure on Polish and Romanian crossing points remains high because they are being used to transport desperately needed grain stocks out of Ukraine after Black Sea ports were blocked, Frontex said.
This is made more complicated by the fact that EU and Ukrainian railways have different track widths and grain wagons have to be unloaded or have their wheels replaced.
Frontex said it had stationed about 350 officers along the Ukrainian border, including in Romania and non-EU member Moldova, to “support evacuation corridors” for refugees.
Western Ukraine is home to more than 1.5 million people displaced in their own country by the conflict. The area has been spared the worst of the fighting but has been pounded by Russian missile strikes.
About 29,000 people crossed into Romania in the first week of June, compared to 30,000 who went the other way. The same pattern was true of Slovakia.
However, an exception was Hungary where arriving Ukrainians continued to slightly outnumber returnees.
Many others are displaced in southern and eastern Ukraine, where hundreds of thousands of people fled the port of Mariupol during a weeks-long Russian siege.
The UN says women and children account for 90 per cent of those who have fled abroad, with men aged 18 to 60 eligible for military service and unable to leave.
