The Hub 3 is a basic router and its Wi-Fi performance isn't the best. Unless yours has a hardware fault getting a new one isn't likely to help - age has little to do with it.
Various factors can cause Wi-Fi drop outs including range (which isn't likely here as you say you're close to the hub) software bugs, device chipset incompatibility, channel utilization, processing performance and interference.
There may be a neighbouring hub causing contention issues or other sources of noise including microwave ovens and baby monitors.
You can do some housekeeping such as;
- Wi-Fi 'survey' with a free scanning/analyzer app - see if there are other hubs/APs on same channels
- Separate 2.4 and 5GHz bands with different SSIDs
- Change channels (turn off auto optimization/smart/intelligent settings as they don't always get it right)
- Check all devices have Wi-Fi driver/firmware updates
Your other option, which many go for, is to use your own third party router/Wi-Fi equipment with the hub in modem mode.
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I know a bit about Wi-Fi, Telecoms, and TV as I used to do it for a living but I'm not perfect so don't beat me up... If you make things you make mistakes!