PPG stream of Polar Verity Sense: Decoding problem in some delta frames

[BioSignD]

Platform your question concerns:

• Android
• iOS
• Other
• [x ] Platform is not relevant for this question

Device:

• Polar OH1
• [x ] Polar Verity Sense
• Polar H10
• Polar H9
• Other
• Device is not relevant for this question

Description:
I am trying to decode a PPG stream from the Polar Verity Sense (I am using Delphi RAD Studio). Streaming works and most of the data frames seem correct and result in a reliable signal (4 channels, compressed delta frames type 0, 10 bit delta, 0x29 samples).

Some frames have an 8-bit delta frame and often only a few samples, e.g. only 2, although the same or a similar number of bytes are transmitted in the frame as with 0x29 samples, see example. The resulting PPG signal looks also interrupted. What could be the problem?

01;0E;1E;98;BE;EA;36;ED;0A;80;3B;5E;06;06;64;05;BA;C3;05;94;0C;00;08;02;F9;75;42;CA;37;6D;70;3A;0A;27;29;48;F0;80;F5;24;14;BF;FB;06;A7;4B;A0;3D;F2;BB;43;8E;36;0B;EF;C6;AB;EC;F3;3B;3F;3D;75;15;3A;F7;8B;AC;02;C1;96;6B;AD;F7;17;B7;EA;EA;09;FE;36;DC;F1;EA;30;5F;0C;F1;0B;45;9F;4D;B2;0B;00;DF;CC;B0;EA;82;A7;2D;B8;15;43;BB;6E;B8;F5;3A;57;2D;75;F7;F5;27;EE;38;FB;B6;53;2F;7A;07;67;47;AF;FB;05;82;9F;DF;BA;FE;ED;FB;FD;BA;FD;C3;8B;9F;7C;0F;B1;BF;DE;F8;EC;E7;CB;3F;41;12;81;93;CE;B6;E1;0A;F0;AE;01;15;BE;7F;DF;37;FC;A5;83;1F;FE;02;1D;58;9F;BE;01;EB;4F;71;01;FF;F1;D7;DE;7E;06;EA;2F;D0;BF;00;F4;B3;5F;00;F5;19;6C;30;43;04;76;60;01;00;15;DB;6F;7F;42;E9;11;34;71;83;15;36;A8;C0;C2;05;BB;8F;60;41;F1;