GPS update rate period spikes higher in Arduplane 4.0 compared with 3.9.3

Hi, I updated my Arduplane from 3.9.3 to Arduplane 4.0.0 on an OmnibusF4 V3 board (without current sensor) equipped with Beitian BN-880 gps.
After the update I noticed from the GPA.Delta log that there are spikes (exactly every 20 seconds) of the update rate period of the GPS that go above 250 ms and they generate a “Bad GPS Signal Health” warning.
In Arduplane 3.9.3 I have random spikes of the update rate period but they do not go above 250 ms and they stays below 220 ms -> no “Bad GPS Signal Health” warning.
How can I solve this issue?
I tried several things like using a different GPS, increasing the update rate from 5 HZ to 10 Hz, using one/two constelations instead of three but I have the same issue.

As soon as I switch back to an Arduplane older than 3.9.6 (if I’m not wrong about the exact version…but something between 3.9.3 and 3.9.6) everything works ok without “Bad GPS Signal Health” warning or update rate period above 220 ms.
Attached some pictures of the GPS.Delta showing the behaviour in Arduplane 4.0 (spikes every 20 sec that go above 250 ms of update rate period) and 3.9.3.
Thank you.

I saw that with arducopter, it is related to GPS_AUTO_CONFIG (trying to inject configuration to GPS every 20sec).

Set it to 0 to disable the feature and check if it change something. It could be a bug.

You can set the default GPS configuration with u-Center. Some options are only available with u-Center. Be aware to set a valid configuration depending on your GPS performance. (M8N refresh rate with 2 GPS system and SBAS is 5hz. If you want to have 3 GPS system, refresh is 3hz and not valid with arduxx).

Hi, thank you for the answer.
I forgot to mention (to keep the post short) that with my trials, just to be sure to compare everything with the same settings for the GPS, I always used GPS_AUTO_CONFIG = 0 and GPS_SAVE_CONFIG = 0.
For this reason I do not think that GPS_AUTO_CONFIG is the cause of this spikes.

Another thing I have noticed is that, if I increase the update rate from 5Hz to 10Hz using only one constellation (GPS), the spikes happens every 10 sec (exactly half time compared with 5Hz).

I’m really not able to solve this issue and I do not feel comfortable to fly a plane with this issue.

Still not able to solve the issue above.

Attached a log with the following:

  1. Arduplane 4.0.4
  2. 30 minutes long
  3. GPS used.The black round shape from Banggood
  4. Only board and gps connected
  5. Board and gps sitting on the balcony
  7. No compass connected or enabled

I have the issue described in the post above starting from Arduplane 3.9.X…where X>3