Mis-Matching Personalities

Sometimes when morphed, Rangers do things that are un-characteristic. It is because of the original Japanese footage. This happened more during the first Saban era, where they used footage and the characters weren't similar and they would do things out of character.

Billy/Dan

Billy was the genius and Dan was much braver, and not stupid but not exactly the inventor Billy was. Dan acted much braver in footage they used for earlier episodes when Billy was scared. 'Zyu2' footage showed off a smarter Blue Ranger.

Adam, Aisha and Rocky

When the trio joined the team, the stunt actors weren't changed so their heights didn't change even though the two trios had significant height changes (most notable Trini and Aisha). Also they didn't look different in the Zyuranger footage, especially when they called the Thunderzords. Now that is just height, but when they morphed, using old footage, they had the same personalities as their pervious counterparts.

Carter/ Matoi
Carter was a straight-forward goody-good corn-fed white boy leader. Matoi was a bit more lenient and fun-loving, but just as stern leader. In the episode "Up to the Challenge" of Lightspeed Rescue, Red Ranger gives Kelsey a 'noogie' which was originally brotherly love between Matoi and his brother in GoGoV but in Lightspeed, it was out of character. It stood out a lot.

Mack Hartford / Satoru Akashi
Not exactly that obvious but Mack and Akashi were different kinds of leaders. Mack was young and inexperienced and when un-morphed, he didn't read 'lead' the way Akashi would. He seemed more like he knew what he was doing when morphed. Akashi was a stalwart and experienced leader.

Ronny / Natsuki Mamiya 
 In the case of Natsuki and Ronnie, they cut out Natsuki's poses and it was easier with the females, they would cut many episodes so it wasn't so noticeable. Natsuki's origin made her prominent and same in PROO but with no reason. Ronny was kidnapped twice with no other explanation that she was 'powerful' and the villains had more reason to kidnap Natsuki because she was a princess of an ancient civilization and she really did have power.

Gem / Hiroto and Gema / Miu
The two counterparts were completely different, Gem and Gema were happier and Hiroto and Miu were serious but this didn't come out much in footage. All the footage of Go-On Wings rejecting the main team was not used. But I put them here anyway to show significant differences between characters after adaption. And showing how writers can change the characteristics and use the appropriate footage and not let cracks slip by.

I'm sure there are more, but those are the ones I remember.