Hello I've seen that for a lot of sentences you've translated from a lot of difference languages, even some very rare one like here in low saxon. As it's very unlikely you speak that many languages, I think it's rather because you don't know yet that in Tatoeba the language at the top is the one you're translating from.

Because let's admit we have

at the top

Elles mangent une pomme (that's French)

then below

They're eating an apple (green arrow)

if you click directly on the translate button to add

他们在吃苹果

then you're actually adding the Chinese translation to the French one not to the English one. And here that would be actually wrong

because the French sentence means 她们 (and not 他们 ) , so what you should actually do is first clicking on the English in order to set it as the main one, and then translate :), because otherwise as you can see with my example it's very likely to add some bad linking between languages.

Of course we do know that with the current interface, that's not something straightforward to understand and I do not blame you.

After of course if you do speak all this language just tell me :) (precising the languages you speak in your profile may help also a lot users)