I recently started shaving with a real straight razor after using a replaceable blade straight for about a year. I purchased a used Baurmann Sohnne 5/8. The blade popped hairs off my arm after receiving it. After stropping the razor passed the HHT but midway through the shave it was like it became dull. After stropping it again it still passed the HHT. So I did a shave test again a couple days later. Still became dull mid way. Any suggestions?