If you use the Stryd as a native Ant+ (bicycle) power sensor, you will get the spikes. If you use the Stryd Power data field which creates its own connection to the Stryd, you will not get the spikes.
If you use Datarun Premium, you can download the Copy 1 with 7 data fields. On my request, a spike filter was added to two of the available power fields in that version. The first one is the field which shows average power for a configurable number of seconds. The other one is a newly added field which shows instant power, but spike filtered.
copy from other thread ;-)
So the average power and power for each lap after the workout when I look at it from GC or TP looks normal. But it’s when the workout is in session, the power on the datafield is abnormall. I emailed Joop who is the developer of the datarun connect in field and he said that it’s not a easy fix to adjust the lap power issue. This seems more to be a Issue Garmin need to fix in their fw. I attached a screen shot of my watch showing the high lap power.
no problem downgrading for the Fenix platform
follow instructions here fenix-5-5s-plus-5-58-beta-release
something like written here fenix-5x-plus-downgrade-firmware-fenix-5x-plus
but first do contact Garmin support so they know about the problem and are able logging it