A couple of thoughts. One, it may pay to check the hydraulic fluid level of the mechanism.
I had a similar situation with my top where it wasn't reset properly. I was doing work on it for the season, which involved operating the top part way and disconnecting the battery to do the work. The top misbehaved after the battery was reconnected. What I'm thinking is that it may be worthwhile to secure the top in the proper up position, then disconnect and reconnect the battery to reset the system.
If your mechanism is anything like my top, there's a spot where you can slip a 10 mm wrench to release the conv deck lid. There may be a fault in the latch mechanism which may be obvious once you have a look at it. I had a problem where the hydraulic cylinder blew a seal.
If none of these easy procedures cures the problem, then the diagnosis gets more complicated and is best left for the dealer.
95 E320 Cabriolet, 131K