Asset autocomplete not working

we’ve successful installed the latest version of rt and asset extension but autocomplete is not working on assets.
For example if we try to link one asset to one other on the “Depends on” field the autocomplete is fetching only the assets with ID between #1 and #15.

We have about 400 assets and all the assets with ID > 15 are not shown on the autocomplete list.

Do you have any idea of the possible cause of this issue?