The only thing weird here is that if you use the same tool to see fees on which network is higher, you get a different results.
Blockcypher reports higher fee on mainnet compared to testnet
0.00069 BTC/KB vs
0.00032 BTC/KBmempool.space reports higher fee on testnet compared to mainnet
25 sat/vB vs
47 sat/vBSometimes these fee estimators either have bugs or use different methodology that returns different fee estimation. I believe mempool.space is more accurate though.
It's like this with Bitcoin too for these estimators. Bitcoin Core's estimator is likely the worst offender.
All that matters is what their client can see. (I've clearly had this bite me in the ass a few times on main net.)