bitcoin core – estimatesmartfee differs a lot on testnet4

I have two testnet4 nodes, both running Bitcoin Core v30.2 and I use estimatesmartfee API calls to guess fees on the network.

I have noticed over time that the estimates vary widely on both nodes and sometimes also by the conf_target.

Is there any possibility to make this estimate more reliable?

E.g. it currently return on node01:

$ bitcoin-cli estimatesmartfee 3 economical
{
  "feerate": 0.00000974,
  "blocks": 3
}

$ bitcoin-cli estimatesmartfee 10 economical
{
  "feerate": 0.00100314,
  "blocks": 10
}

$ bitcoin-cli estimatesmartfee 50 economical
{
  "feerate": 0.00000988,
  "blocks": 50
}

(please note that the conf_target: 10 has larger fee than for conf_target: 3).

and on node02:

$ bitcoin-cli estimatesmartfee 3 economical 
{
  "feerate": 0.00100369,
  "blocks": 3
}

$ bitcoin-cli estimatesmartfee 10 economical 
{
  "feerate": 0.00063429,
  "blocks": 10
}

$ bitcoin-cli estimatesmartfee 50 economical 
{
  "feerate": 0.00063429,
  "blocks": 50
}