Switching between Citation styles

Hi
When I switch between citation styles in a document the formatting gets messed up.

For example a citation looks this way in APA style-

(Thisse, El Messal, & Perrin-Schmitt, 1987)(Lee, Lowe, Strong, Wergedal, & Glackin, 1999)(Lee et al., 1999; Spicer, Rhee, Cheung, & Lassar, 1996)

When i switch to Nature style it becomes-

122,3.

So the commas are messed up.

I make sure there are no gaps between citations when i insert but this still happens.

Any idea how I can fix this/?

Thanks

It seems like both of the styles are messed up; the APA style should have all the references within the same citation. To achieve this, place your cursor in the first citation and click “Edit”. Then use the search box in the Add/Edit dialog to add the subsequent references to the same citation (they will each appear as blue bubbles in the dialog). After all the references have been added to the first citations, you can delete the subsequent citations.

It seems like you have already done this in the third citation, which contains two references.

seems to work fine for me.

APA style produces:
(Behnke & Jones, n.d.; Shapiro & Smith, 2011; Smith, 2009)

Nature style produces -
1-3