DIAGNOSIS This is often normal, especially on cable internet plans which are asymmetrical (slower upload). However, a huge discrepancy could indicate a setup issue.
FIX First, test speed directly connected to your modem (bypass the eero) to establish your ISP baseline. Then, test wirelessly right next to your main gateway eero. If speeds are similar, the eero is not the bottleneck.
IF THAT DIDN'T WORK Disable all eero Labs features (like Optimize for Conferencing & Gaming) in the app temporarily and re-test. These can sometimes prioritize download traffic in a way that limits uploads during a test.
HEADS UP WiFi 6E (6GHz) is great for download, but many client devices and even some eero satellite connections still use 5GHz for upload, which can be slower. Your upload speed is limited by the weakest link in the chain.