AD9253 does not work properly

I want to use AD9253 in default setting, therefore I do not need SPI configuration. AD9253 is connected to Ultrascale+ MPSoC and I have examined the output clocks and digital output pins by using Integrated Logic Analyzer (ILA) debug core in Vivado. Then I see that the outputs do not work properly and I tried to reset the converter by using SPI port. I first tried to soft reset the converter (0x00 => 0x3C) and digital reset (0x08 => 0x03, 0x08 => 0x00). I am not using any SPI interface but giving the read/writes through FPGA/AD9253 connection. The input clock is around 16.82 MHz and SPI clock is 8.41 MHz. The results after reset are very inconsistent. Sometimes I get reasonable values on DCO,FCO and digital output pins. However, it takes a very short time and most times they do not work properly. Here is a time interval that output signals are consistent and reasonable.

If you can help about what the problem is or how can I deal with it, I appreciate it. I have some suspicions:

1) I might be trying to give SPI commands too early, before the device is powered up. However, I have tried to loop SPI commands to eliminate this probability and the results were the same.

2) Maybe I need to wait between reset commands (between 0x08 => 0x03 and 0x08 => 0x00). However I could not find such warning on datasheet.

3) I should give SPI commands through an SPI interface rather than FPGA connections. However, I checked the signals via oscilloscope and it seems there is no problem.

In addition to these, I have no idea about how to get a read from bidirectional SDIO pin on FPGA, therefore I cannot check if SPI commands have worked or not. I would also appreciate any help on this issue.