"Pomerania" and "1945" are enough to get a sense of where the action was happening. Here is a fragment of the map of the creatively named "East Pomerania and Silesia Offensive, February 8th to April 4th 1945", showing off the northern action. Stargard Szczeciński appears on the map as Штаргард (Shtargard), outlined with a yellow rectangle, in the path of the 61st Army.
Let's take a look at what the 61st Army was doing on this day.
"Forces of the Army reinforced fortifications on the line from the previous day, performed reconnaissance and had shootouts with the enemy. Forces on the left flank regrouped, replacing elements of the 2nd Guards Tank Army."
Oh, what's this? I wonder what happened to all of their tanks. Perhaps the records of the 2nd GTA will tell us more.
"On February 25th, elements of the 2nd GTA transferred their positions to elements of the 61st Army, motorized infantry was marching to new locations, the other part was fighting over Piritz."
Let's dig a little deeper into the situation. The book claims that Bix destroyed 4 "American Lend-Lease tanks". The only Lend-Lease tanks around at the time were the Shermans of the 1st Mechanized Corps so, let's check up on them too.
"Acting under directive #00346/OP from the 1st Baltic Front HQ issued on February 23rd, 1945, the 1st Mechanized Corps of the 2nd Guards Tank Army was transferred under the operative subordination to the 47th Army as of 6:00 on February 25th, 1945, and was concentrated in the regions of Kerkov, Linde, (particularly) Rufen."
That's it. No glorious battle, nothing, just concentration in reserve. Naturally, no tanks are recorded in the "losses" section for that day. The next day, the tanks remain in the forest, with the HQ established at Kerkov.
It would appear that the tanks Bix claimed to have destroyed indeed disappeared, but he had nothing to do with it. Perhaps the presence follows by the absence of tanks was good enough for his commanders to record these kills, perhaps they were desperate to write down some victories and didn't particularly care. Either way, that's another reason why blindly trusting unverified claims is a good way to make a fool of yourself.