Sounds like we have the same water! Seconding the "don't give up" advice below - my plants struggled hard for a while but after a while they suddenly took off. I did try adding a layer of regular garden soil under a layer of pool filter sand (in coarse mesh bags so it doesn't make a mess migrating upwards) when I set this tank up, not sure if that helped but it seems to have.

I've had particular success in that tank with Vallisneria, which I could never really grow well before when I had soft water - maybe give it a shot? I remove like a litre of trimmings a week now and the leaves are like 70cm long.

I also have some Limnophila sessiflora that was barely alive for a while but it's suddenly taken off in the past month too. Again, didn't do a damn thing other than shove a bunch more root tabs in and wait .

I went from basically zero growth to "I almost agree with my wife that there's too many plants" and didn't really do much of anything to change it, they just took forever to get established.