Fender ’64 Custom Deluxe Reverb 2018 fuse issue?

Hi everyone,

just got a very strange issue about the Fender ’64 Custom Deluxe Reverb amp:

Location: Germany. I had bought a brand new one in the local shop and after about five to six hours of non-consecutive use, the fuse blowd (not during the using, it just couldn't be turned on again). I replaced the fuse, and it happend again after several hours playing. Then I returned the amp, and bought another new one on thomann. Today, the fuse of the new one blowed again. Both amps behaved exactly the same, despite being otherwise normal before the fuse blew. I live in a relatively new apartment with a stable electrical system—no voltage issues at all, and all my other devices work perfectly fine. Plus, I'm using a surge protection power strip, so I don't think it's an issue with my power supply. 

It’s quite surprising to have this happen repeatedly on brand-new ’64 Customs. The two amps have both serials number starting with CR4207xx, both 2018 production. I don't know why I got those NOS twice in Germany. I'll return the amp, and am not asking for a  resolution to this, just wanted to know if anyone get a clue about this?