/u/mjquigley already covered why there weren't similar pockets of German holdouts like in the pacific so I just want to add 2 cases of late holdouts for European theatre standards.

Georgian uprising in Texel

One example of 'late' fighting was the Georgian uprising in Texel. Texel is one of the Frisian Islands (although technically it is part of North-Holland) in the Wadden Sea.

Georgians in Texel? Yes they were formed into a batallion after being captured in 1941/1942. They choose to fight for the Germans instead of becoming PoW's (and with the rate of death for PoW on the Eastern Front not the dumbest decision). As part of the Atlantic Wall they got stationed in Texel.

On April the 5th they rose up against the Germans, there were 800 Georgians and 400 Germans on the island and they were stationed in the same barracks. The Georgians took control of the entire island but failed to capture 2 artillery batteries in the dunes which the Germans used to start shelling them. The Germans dispatched 2000 soldiers from the mainland to Texel and over the next 5 weeks they retook the island. The Canadians arrived on May the 20th and captured the island after the Germans quickly surrendered to them (the capitulation of the Germans happened on May the 5th in the Netherlands and May the 8th in general). The island suffered major damage and this was considered (one of) the last battles on the European theatre.

Svalbard

Another 'holdout' was Svalbard/Spitsbergen (an archipelago in the arctic) where the Germans had established a few meteorological stations. The Germans lost radio contact in May and were only able to radio in support in August. They surrendered to a Norwegian Seal Hunting vessel on the 4th of September and were considered the last German troops to surrender.

Wasn't there a running battle between the ROA and the Russians in Hungary? I seem to recall something about them continuing the fight to avoid repatriation.

Two other items come to mind that may apply.

Bandera's partisans continued fighting the Russians for Ukrainian independence into the 50's.

The "wandering kampfgruppe". An isolated pocket of German troops trying to find the front lines from Belarus. This may have been a Russian intelligence ploy that has been accepted as true-ish over the years. Does anyone have more on these?