Depends on the CPU/APU being tested and the type of CPU Cooler you have installed. But as long as it didn't go above more than 94.5c (found out this the temperature where the APU starts to throttle) and stayed at that temperature, it seems to be fine. That is way below the Max temperature of 105c and from being throttled by the APU.
Remember your APU was running at 100% load all the time which doesn't occur in usual computer use like browsing or watching videos, etc. Even while gaming, I don't believe the APU will be running at 100% load constantly. As the load goes down so does the temperature.
If you are concern about the APU temperature, If your computer case has the room, try installing a 3rd party CPU Cooler like Cooler Master Hybrid 212 EVO which is inexpensive and one of the best air CPU coolers in the market.
The best cooling is Water cooling. But they tend to be expensive plus you need room to install the Radiator in your computer case.
Here is a very good review by Tom's Hardware that used Prime95 and other software to stress Ryzen 2200g APUs. It seems to have similar temps as you had running Prime95: Combined Stress Testing: Benchmarks & Results - AMD Raven Ridge Thermal/Power Analysis: Ryzen CPUs W...
Copied from Tom's Hardware Review in link:
AMD Ryzen 3 2200G
After ~6 minutes, AMD’s Ryzen 3 2200G hits 95°C. That's well above its thermal limit. And the result doesn't change, even when we push the fan to its fastest rotational speed. With that said, the processor doesn't falter; it keeps going, albeit at an uncomfortably high temperature.
The hottest voltage converters toe the 80°C mark. Average power consumption is close to 88W, while peak power use falls just shy of the 100W threshold.
Plotting frequency over time shows us that the Zen cores slow down slightly once the processor exceeds 94.5W. However, Ryzen does balance this demanding workload well; the missing 100 MHz toward the end of our test is no big deal, particularly since Radeon Vega Graphics isn't affected at all.
In the end, AMD's stock cooler passes our test in a photo finish, with the Zen cores dialing back just a touch.
So your Ryzen Temperatures using Prime95 are normal for that software and Stock CPU Cooler.