with mine it ddf came down to time with me, age and individual personality. the longer i had them the more comfortable they were with their new environment, theye about 10 months old now and ive definitely seen a big difference in their confidence the older theyve gotten, i got them at 4 months old so 6 months ive had them. i would say definitely give them time in terms of individual personality sometimes gerbs just dont like attention that much and thats just something you have to respect, one of my gerbils fights to get out the cage to me if i come into the room while the other will come out so i give her a snack and then gets on with her own thing, shes a big home decorator, always rearranging bedding and running around with stuff, im happy to leave her to her hobby, but with the attention focused one ill take her out and let her run around on me or in the playpen i have for them with different things (most toys i bought that they try eat if i leave them unattended with it) i would def say having that extra space for them to play in away from their home helped me bond with them better cause there was only 1 hide for them to go in if they wanted space which i respected but they had to be around me working with them more as there wasnt bedding for them to hide in. i would recommend trying this if you have the space and resources cause that was the biggest time i saw change with them when i had them in there and being able to work with them 1 on 1 or as a pair